The M16 rifle (officially designated Rifle, Caliber 5.56 mm, M16) is a family of
military rifles adapted from the
ArmaLite AR-15
The ArmaLite AR-15 is a select-fire, gas-operated, air-cooled, magazine-fed rifle manufactured in the United States between 1959 and 1964. Designed by American gun manufacturer ArmaLite in 1956, it was based on its AR-10 rifle. The ArmaLite ...
rifle for the
United States military
The United States Armed Forces are the military forces of the United States. The armed forces consists of six service branches: the Army, Marine Corps, Navy, Air Force, Space Force, and Coast Guard. The president of the United States is the ...
. The original M16 rifle was a
5.56×45mm automatic rifle with a 20-round magazine.
In 1964, the M16 entered US military service and the following year was deployed for
jungle warfare operations during the
Vietnam War
The Vietnam War (also known by #Names, other names) was a conflict in Vietnam, Laos, and Cambodia from 1 November 1955 to the fall of Saigon on 30 April 1975. It was the second of the Indochina Wars and was officially fought between North Vie ...
.
In 1969, the M16A1 replaced the
M14 rifle to become the US military's standard
service rifle
A service rifle (or standard-issue rifle) is a rifle a military issues to regular infantry. In modern militaries, this is typically a versatile and rugged battle rifle, assault rifle, or carbine suitable for use in nearly all environments. Most ...
.
[Urdang, p. 801.] The M16A1 incorporated numerous modifications including a bolt-assist, chrome-plated bore, protective reinforcement around the magazine release, and revised flash hider.
In 1983, the
US Marine Corps adopted the M16A2 rifle and the
US Army
The United States Army (USA) is the land service branch of the United States Armed Forces. It is one of the eight U.S. uniformed services, and is designated as the Army of the United States in the U.S. Constitution.Article II, section 2, cla ...
adopted it in 1986. The M16A2 fires the improved 5.56×45mm (M855/SS109) cartridge and has a newer adjustable rear sight, case deflector, heavy barrel, improved
handguard, pistol grip and
buttstock, as well as a semi-auto and three-round burst fire selector. Adopted in July 1997, the M16A4 is the fourth generation of the M16 series. It is equipped with a removable carrying handle and
Picatinny rail
The Picatinny rail ( or ), or Pic rail for short, also known as a MIL-STD-1913 rail, 1913 rail or STANAG 2324 rail (cancelled), is a military standard rail interface system that provides a mounting platform for firearm accessories. It was o ...
for mounting optics and other ancillary devices.
The M16 has also been widely adopted by other armed forces around the world. Total worldwide production of M16s is approximately 8 million, making it the most-produced firearm of its 5.56 mm caliber.
The
US military has largely replaced the M16 in frontline combat units with a shorter and lighter version, the
M4 carbine
The M4 carbine (officially Carbine, Caliber 5.56 mm, M4) is a 5.56×45mm NATO, gas-operated, magazine-fed carbine developed in the United States during the 1980s. It is a shortened version of the M16A2 assault rifle.
The M4 is extensively ...
.
In April 2022, the U.S. Army selected the
SIG MCX SPEAR The SIG MCX-SPEAR is a multi-caliber rifle developed by the American division of SIG Sauer from the SIG MCX series of carbines. The SIG MCX-SPEAR is primarily chambered in .277 SIG FURY and can be adapted to 7.62×51mm NATO and 6.5mm Creedmoor wit ...
as the winner of the
Next Generation Squad Weapon Program
The Next Generation Squad Weapon (NGSW) program is a United States military program created in 2017 to replace the 5.56mm M4 carbine and M249 SAW light machine gun and the 7.62mm M240 machine gun, with a common system of 6.8mm cartridges; and t ...
to replace the M16/M4. The rifle is designated
XM5
The XM5 is the U.S. Army variant of the SIG MCX Spear, a .277 Fury, 6.8×51mm (.277 in), gas-operated reloading, gas-operated, magazine (firearms), magazine-fed, assault rifle designed by SIG Sauer for the Next Generation Squad Weapon Program in ...
.
History
Background
In 1928, a U.S. Army 'Caliber Board' conducted firing tests at
Aberdeen Proving Ground and recommended transitioning to smaller caliber rounds, mentioning in particular caliber. Largely in deference to tradition, this recommendation was ignored and the Army referred to the caliber as "full sized" for the next 35 years.
After World War II, the United States military started looking for a single automatic rifle to replace the
M1 Garand
The M1 Garand or M1 rifleOfficially designated as U.S. rifle, caliber .30, M1, later simply called Rifle, Caliber .30, M1, also called US Rifle, Cal. .30, M1 is a semi-automatic rifle that was the service rifle of the U.S Army during World War ...
,
M1/M2 Carbines,
M1918 Browning Automatic Rifle
The Browning Automatic Rifle (BAR) is a family of American automatic rifles and machine guns used by the United States and numerous other countries during the 20th century. The primary variant of the BAR series was the M1918, chambered for the . ...
,
M3 "Grease Gun" and
Thompson submachine gun
The Thompson submachine gun (also known as the "Tommy Gun", "Chicago Typewriter", "Chicago Piano", “Trench Sweeper” or "Trench Broom") is a blowback-operated, air-cooled, magazine-fed selective-fire submachine gun, invented by United Stat ...
.
However, early experiments with select-fire versions of the M1 Garand proved disappointing. During the
Korean War
, date = {{Ubl, 25 June 1950 – 27 July 1953 (''de facto'')({{Age in years, months, weeks and days, month1=6, day1=25, year1=1950, month2=7, day2=27, year2=1953), 25 June 1950 – present (''de jure'')({{Age in years, months, weeks a ...
, the select-fire
M2 carbine largely replaced the
submachine gun
A submachine gun (SMG) is a magazine-fed, automatic carbine designed to fire handgun cartridges. The term "submachine gun" was coined by John T. Thompson, the inventor of the Thompson submachine gun, to describe its design concept as an autom ...
in US service and became the most widely used carbine variant. However, combat experience suggested that the
.30 Carbine
The .30 Carbine (7.62×33mm) is a rimless carbine/rifle cartridge used in the M1 carbine introduced in the 1940s. It is a light rifle round designed to be fired from the M1 carbine's 18-inch (458 mm) barrel.
History
Shortly before World W ...
round was underpowered. American weapons designers concluded that an intermediate round was necessary, and recommended a small-caliber, high-velocity cartridge.
However, senior American commanders, having faced fanatical enemies and experienced major logistical problems during World War II and the Korean War, insisted that a single, powerful .30 caliber cartridge be developed, that could not only be used by the new automatic rifle, but by the new
general-purpose machine gun (GPMG) in concurrent development.
This culminated in the development of the
7.62×51 mm NATO cartridge.
The U.S. Army then began testing several rifles to replace the obsolete M1. Springfield Armory's T44E4 and heavier T44E5 were essentially updated versions of the M1 chambered for the new 7.62 mm round, while
Fabrique Nationale submitted their
FN FAL
The FAL (a French acronym for (English: "Light Automatic Rifle")), is a battle rifle designed in Belgium by Dieudonné Saive and manufactured by FN Herstal (simply known as FN).
During the Cold War the FAL was adopted by many countries of th ...
as the
T48.
ArmaLite
ArmaLite, or Armalite, is an American small arms engineering company, formed in the early 1950s, in Hollywood, California. Many of its products, as conceived by chief designer Eugene Stoner, relied on unique foam-filled fiberglass butt/stock fur ...
entered the competition late, hurriedly submitting several
AR-10 prototype rifles in the fall of 1956 to the U.S. Army's Springfield Armory for testing.
[Pikula, pp. 36, 38] The AR-10 featured an innovative straight-line barrel/stock design, forged aluminum alloy receivers and with
phenolic composite stocks.
[Pikula, Major Sam. ''The ArmaLite AR-10''. Regnum Fund Press, 1998. . pp. 27-29] It had rugged elevated sights, an oversized aluminum
flash suppressor and
recoil compensator
A muzzle brake or recoil compensator is a device connected to, or a feature integral to the construction of, the muzzle or barrel of a firearm or cannon that is intended to redirect a portion of propellant gases to counter recoil and unwanted ...
, and an adjustable gas system.
[Pikula, pp. 27-30] The final prototype featured an upper and lower receiver with the now-familiar hinge and takedown pins, and the
charging handle was on top of the receiver placed inside of the carry handle.
For a 7.62 mm NATO rifle, the AR-10 was incredibly lightweight at only empty.
Initial comments by Springfield Armory test staff were favorable, and some testers commented that the AR-10 was the best lightweight automatic rifle ever tested by the Armory.
[Pikula, pp. 39-40] In the end the U.S. Army chose the T44, now named
M14 rifle,
which was an improved M1 Garand with a 20-round magazine and automatic fire capability.
The U.S. also adopted the
M60 general purpose machine gun (GPMG).
Its NATO partners adopted the FN FAL and
HK G3
The Heckler & Koch G3 (''Gewehr'' 3) is a 7.62×51mm NATO, selective fire, select-fire battle rifle developed in the 1950s by the German small arms, armament manufacturer Heckler & Koch (H&K) in collaboration with the Spanish state-owned design ...
rifles, as well as the
FN MAG
The FN MAG is a Belgian 7.62 mm general-purpose machine gun, designed in the early 1950s at Fabrique Nationale (FN) by Ernest Vervier. It has been used by more than 80 countries and it has been made under licence in several countries, inc ...
and
Rheinmetall MG3
The MG 3 is a German general-purpose machine gun chambered for the 7.62×51mm NATO cartridge. The weapon's design is derived from the World War II era MG 42 ''Einheitsmaschinengewehr'' (Universal machine gun) that fired the 7.92×57mm Mauser ...
GPMGs.
The first confrontations between the
AK-47 and the M14 came in the early part of the
Vietnam War
The Vietnam War (also known by #Names, other names) was a conflict in Vietnam, Laos, and Cambodia from 1 November 1955 to the fall of Saigon on 30 April 1975. It was the second of the Indochina Wars and was officially fought between North Vie ...
. Battlefield reports indicated that the M14 was uncontrollable in full-auto and that soldiers could not carry enough ammunition to maintain fire superiority over the AK-47.
And, while the M2 carbine offered a high rate of fire, it was under-powered and ultimately outclassed by the AK-47. A replacement was needed: a medium between the traditional preference for high-powered rifles such as the M14, and the lightweight firepower of the M2 Carbine.
As a result, the Army was forced to reconsider a 1957 request by General
Willard G. Wyman, commander of the U.S. Continental Army Command (CONARC) to develop a .223-inch caliber (5.56 mm) select-fire rifle weighing when loaded with a 20-round magazine.
The 5.56 mm round had to penetrate a standard U.S.
helmet at 500 yards (460 meters) and retain a velocity in excess of the speed of sound, while matching or exceeding the wounding ability of the .30 Carbine cartridge.
This request ultimately resulted in the development of a scaled-down version of the
Armalite AR-10
The ArmaLite AR-10 is a 7.62×51mm NATO battle rifle designed by Eugene Stoner in the late 1950s and manufactured by ArmaLite (then a division of the Fairchild Aircraft Corporation). When first introduced in 1956, the AR-10 used an innovative c ...
, named the
ArmaLite AR-15
The ArmaLite AR-15 is a select-fire, gas-operated, air-cooled, magazine-fed rifle manufactured in the United States between 1959 and 1964. Designed by American gun manufacturer ArmaLite in 1956, it was based on its AR-10 rifle. The ArmaLite ...
.
The AR-15 was first revealed by
Eugene Stoner
Eugene Morrison Stoner (November 22, 1922 – April 24, 1997) was an American firearms designer who is most associated with the development of the ArmaLite AR-15 rifle that was redesigned and modified by Colt's Patent Firearm Company (now known ...
at Fort Benning in May 1957. The AR-15 used .22-caliber bullets, which destabilized when they hit a human body, as opposed to the .30 round, which typically passed through in a straight line. The smaller caliber meant that it could be controlled in autofire due to the reduced
bolt thrust and
free recoil
Free recoil is a vernacular term or jargon for recoil energy of a firearm not supported from behind. Free recoil denotes the translational kinetic energy (''Et'') imparted to the shooter of a small arm when discharged and is expressed in joules ( ...
impulse. Being almost one-third the weight of the .30 meant that the soldier could sustain fire for longer with the same load. Due to design innovations, the AR-15 could fire 600 to 700 rounds a minute with an extremely low jamming rate. Parts were stamped out, not hand-machined, so could be mass-produced, and the stock was plastic to reduce weight.
In 1958, the Army's
Combat Developments Experimentation Command
Combat ( French for ''fight'') is a purposeful violent conflict meant to physically harm or kill the opposition. Combat may be armed (using weapons) or unarmed ( not using weapons). Combat is sometimes resorted to as a method of self-defense, or ...
ran experiments with small squads in combat situations using the M14, AR-15, and another rifle designed by Winchester. The resulting study recommended adopting a lightweight rifle like the AR-15. In response, the Army declared that all rifles and machine guns should use the same ammunition, and ordered full production of the M-14.
However, advocates for the AR-15 gained the attention of Air Force Chief of Staff General
Curtis LeMay. After testing the AR-15 with the ammunition manufactured by Remington that Armalite and Colt recommended, the Air Force declared that the AR-15 was its 'standard model' and ordered 8,500 rifles and 8.5 million rounds.
Advocates for the AR-15 in the
Defense Advanced Research Projects Agency
The Defense Advanced Research Projects Agency (DARPA) is a research and development agency of the United States Department of Defense responsible for the development of emerging technologies for use by the military.
Originally known as the Adv ...
acquired 1,000 Air Force AR-15s and shipped them to be tested by the
Army of the Republic of Vietnam
The Army of the Republic of Vietnam (ARVN; ; french: Armée de la république du Viêt Nam) composed the ground forces of the Republic of Vietnam Military Forces, South Vietnamese military from its inception in 1955 to the Fall of Saigon in April ...
(ARVN). The South Vietnam soldiers issued glowing reports of the weapon's reliability, recording zero broken parts while firing 80,000 rounds in one stage of testing, and requiring only two replacement parts for the 1,000 weapons over the entire course of testing. The report of the experiment recommended that the U.S. provide the AR-15 as the standard rifle of the ARVN, but Admiral
Harry Felt
Admiral Harry Donald Felt (June 21, 1902 – February 25, 1992) was an aviator in the United States Navy who led U.S. carrier strikes during World War II and later served as commander in chief of Pacific Command (CINCPAC) from 1958 to ...
, then Commander in Chief, Pacific Forces, rejected the recommendations on the advice of the U.S. Army.
Throughout 1962 and 1963, the U.S. military extensively tested the AR-15. Positive evaluations emphasized its lightness, "lethality", and reliability.
However, the
Army Materiel Command criticized its inaccuracy at longer ranges and lack of penetrating power at higher ranges.
In early 1963, the
U.S. Special Forces
The United States Army Special Forces (SF), colloquially known as the "Green Berets" due to their distinctive service Berets of the United States Army, headgear, are a special operations special operations force, force of the United States Ar ...
asked, and was given permission, to make the AR-15 its standard weapon. Other users included Army Airborne units in Vietnam and some units affiliated with the
Central Intelligence Agency
The Central Intelligence Agency (CIA ), known informally as the Agency and historically as the Company, is a civilian foreign intelligence service of the federal government of the United States, officially tasked with gathering, processing, ...
. As more units adopted the AR-15, Secretary of the Army
Cyrus Vance
Cyrus Roberts Vance Sr. (March 27, 1917January 12, 2002) was an American lawyer and United States Secretary of State under President Jimmy Carter from 1977 to 1980. Prior to serving in that position, he was the United States Deputy Secretary of ...
ordered an investigation into why the weapon had been rejected by the Army. The resulting report found that Army Materiel Command had rigged the previous tests, selecting tests that would favor the M14 and choosing
match grade M14s to compete against AR-15s out of the box.
At this point, the bureaucratic battle lines were well-defined, with the Army ordnance agencies opposed to the AR-15 and the Air Force and civilian leadership of the Defense Department in favor.
In January 1963, Secretary of Defense Robert McNamara concluded that the AR-15 was the superior weapon system and ordered a halt to M14 production.
In late 1963, the Defense Department began mass procurement of rifles for the Air Force and special Army units. Secretary McNamara designated the Army as the procurer for the weapon with the Department, which allowed the Army ordnance establishment to modify the weapon as they wished. The first modification was the addition of a "manual bolt closure," allowing a soldier to ram in a round if it failed to seat properly. The Air Force, which was buying the rifle, and the Marine Corps, which had tested it both objected to this addition, with the Air Force noting, "During three years of testing and operation of the AR-15 rifle under all types of conditions the Air Force has no record of malfunctions that could have been corrected by a manual bolt closing device." They also noted that the closure added weight and complexity, reducing the reliability of the weapon. Colonel Harold Yount, who managed the Army procurement, would later state the bolt closure was added after direction from senior leadership, rather than as a result of any complaint or test result, and testified about the reasons: "the M-1, the M-14, and the carbine had always had something for the soldier to push on; that maybe this would be a comforting feeling to him, or something."
After modifications,
the new redesigned rifle was subsequently adopted as the M16 Rifle.
Despite its early failures the M16 proved to be a revolutionary design and stands as the longest continuously serving rifle in US military history.
It has been adopted by many US allies and the
5.56×45 mm NATO cartridge has become not only the NATO standard, but "the standard assault-rifle cartridge in much of the world."
It also led to the development of small-caliber high-velocity service rifles by every major army in the world.
It is a benchmark against which other assault rifles are judged.
Colt, H&R and GM Hydramatic Division manufactured M16A1 rifles during the
Vietnam War
The Vietnam War (also known by #Names, other names) was a conflict in Vietnam, Laos, and Cambodia from 1 November 1955 to the fall of Saigon on 30 April 1975. It was the second of the Indochina Wars and was officially fought between North Vie ...
.
M16s were produced by Colt until the late 1980s, when FN Herstal (FN USA) began to manufacture them.
Adoption
In July 1960, General
Curtis LeMay was impressed by a demonstration of the ArmaLite AR-15. In the summer of 1961, General LeMay was promoted to U.S. Air Force chief of staff, and requested 80,000 AR-15s. However, General
Maxwell D. Taylor
Maxwell Davenport Taylor (August 26, 1901 – April 19, 1987) was a senior United States Army officer and diplomat of the mid-20th century. He served with distinction in World War II, most notably as commander of the 101st Airborne Division, ni ...
,
chairman of the Joint Chiefs of Staff
The chairman of the Joint Chiefs of Staff (CJCS) is the presiding officer of the United States Joint Chiefs of Staff (JCS). The chairman is the highest-ranking and most senior military officer in the United States Armed Forces Chairman: app ...
, advised President
John F. Kennedy
John Fitzgerald Kennedy (May 29, 1917 – November 22, 1963), often referred to by his initials JFK and the nickname Jack, was an American politician who served as the 35th president of the United States from 1961 until his assassination i ...
that having two different calibers within the military system at the same time would be problematic and the request was rejected.
In October 1961, William Godel, a senior man at the
Advanced Research Projects Agency, sent 10 AR-15s to South Vietnam. The reception was enthusiastic, and in 1962 another 1,000 AR-15s were sent.
United States Army Special Forces
The United States Army Special Forces (SF), colloquially known as the "Green Berets" due to their distinctive service Berets of the United States Army, headgear, are a special operations special operations force, force of the United States Ar ...
personnel filed battlefield reports lavishly praising the AR-15 and the stopping-power of the 5.56 mm cartridge, and pressed for its adoption.
The damage caused by the 5.56 mm bullet was originally believed to be caused by "tumbling" due to the slow 1 turn in rifling twist rate.
However, any pointed lead core bullet will "tumble" after penetration in flesh, because the center of gravity is towards the rear of the bullet. The large wounds observed by soldiers in Vietnam were actually caused by bullet fragmentation created by a combination of the bullet's velocity and construction. These wounds were so devastating, that the photographs remained classified into the 1980s.
However, despite overwhelming evidence that the AR-15 could bring more firepower to bear than the M14, the Army opposed the adoption of the new rifle.
U.S.
Secretary of Defense
A defence minister or minister of defence is a cabinet official position in charge of a ministry of defense, which regulates the armed forces in sovereign states. The role of a defence minister varies considerably from country to country; in som ...
Robert McNamara now had two conflicting views: the ARPA report favoring the AR-15 and the Army's position favoring the M14.
Even President Kennedy expressed concern, so McNamara ordered Secretary of the Army
Cyrus Vance
Cyrus Roberts Vance Sr. (March 27, 1917January 12, 2002) was an American lawyer and United States Secretary of State under President Jimmy Carter from 1977 to 1980. Prior to serving in that position, he was the United States Deputy Secretary of ...
to test the M14, the AR-15 and the AK-47. The Army reported that only the M14 was suitable for service, but Vance wondered about the impartiality of those conducting the tests. He ordered the Army inspector general to investigate the testing methods used; the inspector general confirmed that the testers were biased towards the M14.
In January 1963, Secretary McNamara received reports that M14 production was insufficient to meet the needs of the armed forces and ordered a halt to M14 production.
At the time, the AR-15 was the only rifle that could fulfill a requirement of a "universal" infantry weapon for issue to all services. McNamara ordered its adoption, despite receiving reports of several deficiencies, most notably the lack of a
chrome-plated
Chrome plating (less commonly chromium plating) is a technique of electroplating a thin layer of chromium onto a metal object. A chrome-plated item is called ''chrome''. The chromed layer can be decorative, provide corrosion resistance, ease o ...
chamber.
![101st Airborne Division - Vietnam 03](https://upload.wikimedia.org/wikipedia/commons/9/91/101st_Airborne_Division_-_Vietnam_03.jpg)
After modifications (most notably, the charging handle was re-located from under the carrying handle like the AR-10, to the rear of the receiver),
the new redesigned rifle was renamed the ''Rifle, Caliber 5.56 mm, M16''.
Inexplicably, the modification to the new M16 did not include a chrome-plated barrel. Meanwhile, the Army relented and recommended the adoption of the M16 for jungle warfare operations. However, the Army insisted on the inclusion of a
forward assist to help push the bolt into battery in the event that a cartridge failed to seat into the chamber. The Air Force, Colt and Eugene Stoner believed that the addition of a forward assist was an unjustified expense. As a result, the design was split into two variants: the Air Force's M16 without the forward assist, and the XM16E1 with the forward assist for the other service branches.
In November 1963, McNamara approved the U.S. Army's order of 85,000 XM16E1s;
and to appease General LeMay, the Air Force was granted an order for another 19,000 M16s.
In March 1964, the M16 rifle went into production and the Army accepted delivery of the first batch of 2,129 rifles later that year, and an additional 57,240 rifles the following year.
In 1964, the Army was informed that
DuPont
DuPont de Nemours, Inc., commonly shortened to DuPont, is an American multinational chemical company first formed in 1802 by French-American chemist and industrialist Éleuthère Irénée du Pont de Nemours. The company played a major role in ...
could not mass-produce the
IMR 4475 stick powder to the specifications demanded by the M16. Therefore,
Olin Mathieson Company provided a high-performance
ball propellant. While the Olin WC 846 powder achieved the desired per second muzzle velocity, it produced much more fouling, that quickly jammed the M16's action (unless the rifle was cleaned well and often).
In March 1965, the Army began to issue the XM16E1 to infantry units. However, the rifle was initially delivered without adequate cleaning kits
or instructions because advertising from Colt asserted that the M16's materials made the weapon require little maintenance, and was capable of self-cleaning. Furthermore, cleaning was often conducted with improper equipment, such as
insect repellent, water, and aircraft fuel, which induced further wear on the weapon. As a result, reports of stoppages in combat began to surface.
The most severe problem was known as "failure to extract"—the spent cartridge case remained lodged in the chamber after the rifle was fired.
Documented accounts of dead U.S. troops found next to disassembled rifles eventually led to a Congressional investigation.
In February 1967, the improved XM16E1 was standardized as the M16A1.
The new rifle had a chrome-plated chamber and bore to eliminate corrosion and stuck cartridges, and other minor modifications.
New cleaning kits, powder solvents, and lubricants were also issued. Intensive training programs in weapons cleaning were instituted including a
comic book
A comic book, also called comicbook, comic magazine or (in the United Kingdom and Ireland) simply comic, is a publication that consists of comics art in the form of sequential juxtaposed panels that represent individual scenes. Panels are of ...
-style operations manual. As a result, reliability problems greatly diminished and the M16A1 rifle achieved widespread acceptance by U.S. troops in Vietnam.
In 1969, the M16A1 officially replaced the
M14 rifle to become the U.S. military's standard
service rifle
A service rifle (or standard-issue rifle) is a rifle a military issues to regular infantry. In modern militaries, this is typically a versatile and rugged battle rifle, assault rifle, or carbine suitable for use in nearly all environments. Most ...
.
In 1970, the new WC 844 powder was introduced to reduce fouling.
Reliability
![DIRECTM16](https://upload.wikimedia.org/wikipedia/commons/4/4f/DIRECTM16.gif)
During the early part of its service, the M16 had a reputation for poor reliability and a malfunction rate of two per 1000 rounds fired.
[Hearings, Reports and Prints of the House Committee on Armed Services, Issue 14, Part 1. United States. Congress. House. Committee on Armed Services. U.S. Government Printing Office. 1969. p. 2326.] The M16's action works by passing high-pressure propellant gasses tapped from the barrel down a tube and into the carrier group within the upper receiver, and is commonly referred to as a "
direct impingement gas system". The gas goes from the gas tube, through the bolt carrier key, and into the inside of the carrier where it expands in a donut-shaped gas cylinder. Because the bolt is prevented from moving forward by the barrel, the carrier is driven to the rear by the expanding gases and thus converts the energy of the gas to movement of the rifle's parts. The back part of the bolt forms a piston head and the cavity in the bolt carrier is the piston sleeve. It is more correct to call it an ''internal piston'' system.
This design is much lighter and more compact than a gas-piston design. However, this design requires that combustion byproducts from the discharged cartridge be blown into the receiver as well. This accumulating carbon and vaporized metal build-up within the receiver and bolt-carrier negatively affects reliability and necessitates more intensive maintenance on the part of the individual soldier. The channeling of gasses into the bolt carrier during operation increases the amount of heat that is deposited in the receiver while firing the M16 and causes essential lubricant to be "burned off". This requires frequent and generous applications of appropriate lubricant.
Lack of proper lubrication is the most common source of weapon stoppages or jams.
The original M16 fared poorly in the jungles of
Vietnam
Vietnam or Viet Nam ( vi, Việt Nam, ), officially the Socialist Republic of Vietnam,., group="n" is a country in Southeast Asia, at the eastern edge of mainland Southeast Asia, with an area of and population of 96 million, making i ...
and was infamous for reliability problems in the harsh environment. Max Hastings was very critical of the M16's general field issue in Vietnam just as grievous design flaws were becoming apparent. He further states that the Shooting Times experienced repeated malfunctions with a test M16 and assumed these would be corrected before military use, but they were not. Many Marines and soldiers were so angry with the reliability problems they began writing home and on the 26th of March 1967 the Washington Daily News broke the story. Eventually the M16 became the target of a Congressional investigation. The investigation found that:
* The M16 was issued to troops without cleaning kits or instruction on how to clean the rifle.
* The M16 and 5.56×45 mm cartridge was tested and approved with the use of a DuPont IMR8208M
extruded powder, that was switched to Olin Mathieson WC846
ball powder
Ball propellant (trademarked as Ball Powder by Olin Corporation and marketed as spherical powder by Hodgdon Powder CompanyWootters, John ''Propellant Profiles'' (1982) Wolfe Publishing Company pp.95,101,136-138,141,149&155 ) is a form of nitrocell ...
which produced much more fouling, that quickly jammed the action of the M16 (unless the gun was cleaned well and often).
* The M16 lacked a
forward assist (rendering the rifle inoperable when it failed to go fully forward).
* The M16 lacked a chrome-plated chamber, which allowed corrosion problems and contributed to case extraction failures (which was considered the most severe problem and required extreme measures to clear, such as inserting the cleaning-rod down the barrel and knocking the spent cartridge out).
When these issues were addressed and corrected by the M16A1, the reliability problems decreased greatly.
According to a 1968 Department of Army report, the M16A1 rifle achieved widespread acceptance by U.S. troops in Vietnam.
"Most men armed with the M16 in Vietnam rated this rifle's performance high, however, many men entertained some misgivings about the M16's reliability. When asked what weapon they preferred to carry in combat, 85 percent indicated that they wanted either the M16 or its
maller
Benjamin "Big Ben" Maller (born April 29, 1975) is an American sports radio host who hosts a weekday radio show on Fox Sports Radio, which airs 11pm-3am PT/2am-6am ET. Maller is considered one of the first influential sports bloggers, because of ...
carbine-length version, the
XM177E2." Also "the M14 was preferred by 15 percent, while less than one percent wished to carry either the
Stoner rifle, the AK-47, the
carbine or a pistol."
In March 1970, the "President's Blue Ribbon Defense Panel" concluded that the issuance of the M16 saved the lives of 20,000 U.S. servicemen during the Vietnam War, who would have otherwise died had the M14 remained in service.
However, the M16 rifle's reputation continues to suffer.
Another underlying cause of the M16’s jamming problem was identified by ordnance staff that discovered that Stoner and ammunition manufacturers had initially tested the AR 15 using DuPont IMR8208M extruded (stick) powder. Later ammunition manufacturers adopted the more readily available Olin Mathieson WC846 ball powder. The ball powder produced a longer peak chamber pressure with undesired timing effects. Upon firing, the cartridge case expands and seals the chamber (
obturation
In the field of firearms and airguns, obturation denotes necessary barrel blockage or fit by a deformed soft projectile (obturation in general is closing up an opening). A bullet or pellet, made of soft material and often with a concave base, wi ...
). When the peak pressure starts to drop the cartridge case contracts and then can be extracted. With ball powder, the cartridge case was not contracted enough during extraction due to the longer peak pressure period. The ejector would then fail to extract the cartridge case, tearing through the case rim, leaving an obturated case behind.
After the introduction of the M4 Carbine, it was found that the shorter barrel length of 14.5 inches also has a negative effect on reliability, as the gas port is located closer to the chamber than the gas port of the standard length M16 rifle: 7.5 inches instead of 13 inches.
This affects the M4's timing and increases the amount of stress and heat on the critical components, thereby reducing reliability.
In a 2002 assessment the USMC found that the M4 malfunctioned three times more often than the M16A4 (the M4 failed 186 times for 69,000 rounds fired, while the M16A4 failed 61 times).
Thereafter, the Army and Colt worked to make modifications to the M4s and M16A4s in order to address the problems found.
In tests conducted in 2005 and 2006 the Army found that on average, the new M4s and M16s fired approximately 5,000 rounds between stoppages.
In December 2006, the
Center for Naval Analyses (CNA) released a report on U.S. small arms in combat. The CNA conducted surveys on 2,608 troops returning from combat in Iraq and Afghanistan over the past 12 months. Only troops who had fired their weapons at enemy targets were allowed to participate. 1,188 troops were armed with M16A2 or A4 rifles, making up 46 percent of the survey. 75 percent of M16 users (891 troops) reported they were satisfied with the weapon. 60 percent (713 troops) were satisfied with handling qualities such as handguards, size, and weight. Of the 40 percent dissatisfied, most were with its size. Only 19 percent of M16 users (226 troops) reported a stoppage, while 80 percent of those that experienced a stoppage said it had little impact on their ability to clear the stoppage and re-engage their target. Half of the M16 users experienced failures of their magazines to feed. 83 percent (986 troops) did not need their rifles repaired while in theater. 71 percent (843 troops) were confident in the M16's reliability, defined as level of soldier confidence their weapon will fire without malfunction, and 72 percent (855 troops) were confident in its durability, defined as level of soldier confidence their weapon will not break or need repair. Both factors were attributed to high levels of soldiers performing their own maintenance. 60 percent of M16 users offered recommendations for improvements. Requests included greater bullet lethality, new-built instead of rebuilt rifles, better quality magazines, decreased weight, and a collapsible stock. Some users recommended shorter and lighter weapons such as the
M4 carbine
The M4 carbine (officially Carbine, Caliber 5.56 mm, M4) is a 5.56×45mm NATO, gas-operated, magazine-fed carbine developed in the United States during the 1980s. It is a shortened version of the M16A2 assault rifle.
The M4 is extensively ...
. Some issues have been addressed with the issuing of the
Improved STANAG magazine in March 2009, and the
M855A1 Enhanced Performance Round in June 2010.
In early 2010, two journalists from ''
The New York Times
''The New York Times'' (''the Times'', ''NYT'', or the Gray Lady) is a daily newspaper based in New York City with a worldwide readership reported in 2020 to comprise a declining 840,000 paid print subscribers, and a growing 6 million paid ...
'' spent three months with soldiers and Marines in Afghanistan. While there, they questioned around 100 infantry troops about the reliability of their M16 rifles, as well as the M4 carbine. The troops did not report reliability problems with their rifles. While only 100 troops were asked, they engaged in daily fighting in
Marja, including least a dozen intense engagements in
Helmand Province, where the ground is covered in fine powdered sand (called "moon dust" by troops) that can stick to firearms.
Weapons were often dusty, wet, and covered in mud. Intense firefights lasted hours with several magazines being expended. Only one soldier reported a jam when his M16 was covered in mud after climbing out of a canal. The weapon was cleared and resumed firing with the next chambered round. Furthermore, the Marine Chief Warrant Officer responsible for weapons training and performance of the Third Battalion, Sixth Marines, reported that "We've had nil in the way of problems; we've had no issues", with his
battalion
A battalion is a military unit, typically consisting of 300 to 1,200 soldiers commanded by a lieutenant colonel, and subdivided into a number of companies (usually each commanded by a major or a captain). In some countries, battalions are ...
's 350 M16s and 700 M4s.
Design
The M16 is a lightweight, 5.56 mm, air-cooled,
gas-operated
Gas-operation is a system of operation used to provide energy to operate locked breech, autoloading firearms. In gas-operation, a portion of high-pressure gas from the cartridge being fired is used to power a mechanism to dispose of the spent ...
,
magazine
A magazine is a periodical publication, generally published on a regular schedule (often weekly or monthly), containing a variety of content. They are generally financed by advertising, purchase price, prepaid subscriptions, or by a combinatio ...
-fed
assault rifle, with a
rotating bolt. The M16's receivers are made of
7075 aluminum alloy
7075 aluminium alloy (AA7075) is an aluminium alloy with zinc as the primary alloying element. It has excellent mechanical properties and exhibits good ductility, high strength, toughness, and good resistance to fatigue. It is more susceptible to ...
, its barrel, bolt, and bolt carrier of steel, and its handguards, pistol grip, and buttstock of plastics.
The M16 internal piston action was derived from the original
ArmaLite AR-10
The ArmaLite AR-10 is a 7.62×51mm NATO battle rifle designed by Eugene Stoner in the late 1950s and manufactured by ArmaLite (then a division of the Fairchild Aircraft Corporation). When first introduced in 1956, the AR-10 used an innovative c ...
and
ArmaLite AR-15
The ArmaLite AR-15 is a select-fire, gas-operated, air-cooled, magazine-fed rifle manufactured in the United States between 1959 and 1964. Designed by American gun manufacturer ArmaLite in 1956, it was based on its AR-10 rifle. The ArmaLite ...
actions. This internal piston action system designed by
Eugene Stoner
Eugene Morrison Stoner (November 22, 1922 – April 24, 1997) was an American firearms designer who is most associated with the development of the ArmaLite AR-15 rifle that was redesigned and modified by Colt's Patent Firearm Company (now known ...
is commonly called a
direct impingement system, but it does not use a conventional direct impingement system. In , the designer states: ″This invention is a true expanding gas system instead of the conventional impinging gas system.″
The gas system, bolt carrier, and bolt-locking design were novel for the time.
The M16A1 was especially lightweight at with a loaded 30-round magazine.
[Operator's Manual M16A1 Rifle](_blank)
. flii.by This was significantly less than the M14 that it replaced at with a loaded 20-round magazine. It is also lighter when compared to the
AKM
The AKM () is an assault rifle designed by Soviet small arms designer Mikhail Kalashnikov in 1959. It is the most ubiquitous rifle of the Kalashnikov rifles. It was developed as a replacement to the AK-47 introduced a decade prior.
Introduced ...
's with a loaded 30-round magazine.
The M16A2 weighs loaded with a 30-round magazine,
because of the adoption of a thicker barrel profile. The thicker barrel is more resistant to damage when handled roughly and is also slower to overheat during sustained fire. Unlike a traditional "bull" barrel that is thick its entire length, the M16A2's barrel is only thick forward of the handguards. The barrel profile under the handguards remained the same as the M16A1 for compatibility with the
M203 grenade launcher
The M203 is a single-shot 40 mm under-barrel grenade launcher designed to attach to a rifle. It uses the same rounds as the older stand-alone M79 break-action grenade launcher, which utilizes the high-low propulsion system to keep recoil force ...
.
Barrel
Early model M16 barrels had a
rifling
In firearms, rifling is machining helical grooves into the internal (bore) surface of a gun's barrel for the purpose of exerting torque and thus imparting a spin to a projectile around its longitudinal axis during shooting to stabilize the pro ...
twist of four grooves, right-hand
twist
Twist may refer to:
In arts and entertainment Film, television, and stage
* ''Twist'' (2003 film), a 2003 independent film loosely based on Charles Dickens's novel ''Oliver Twist''
* ''Twist'' (2021 film), a 2021 modern rendition of ''Olive ...
, one turn in 14 inches (1:355.6 mm or 64 calibers) bore—as it was the same rifling as used by the
.222 Remington
The .222 Remington or 5.7×43mm (C.I.P), also known as the triple deuce, triple two, and treble two, is a centerfire rifle cartridge. Introduced in 1950, it was the first commercial rimless .22 (5.56 mm) cartridge made in the United Stat ...
sporting cartridge. After finding out that under unfavorable conditions, military bullets could yaw in flight at long ranges, the rifling was soon altered. Later M16 models and the M16A1 had an improved rifling with six grooves, right-hand twist, one turn in 12 inches (1:304.8 mm or 54.8 calibers) for increased accuracy and was optimized to adequately stabilize the M193 ball and M196 tracer bullets. M16A2 and current models are optimized for firing the heavier NATO SS109 ball and long L110 tracer bullets and have six grooves, right-hand twist, one turn in 7 in (1:177.8 mm or 32 calibers).
Using M193 ball and M196 tracer bullets with a one turn in 7 in (1:177.8 mm or 32 calibers) twist degrades accuracy and should only be used in emergency situations. NATO SS109 ball and L110 tracer bullets should only be used in emergency situations at ranges under with a one turn in 12 inches (1:304.8 mm or 54.8 calibers) twist, as this twist is insufficient to stabilize these projectiles.
Weapons designed to adequately stabilize both the M193 or SS109 projectiles (like civilian market clones) usually have a six-groove, right-hand twist, one turn in 9 inches (1:228.6 mm or 41.1 calibers) or one turn in 8 inches (1:203.2 mm or 36.5 calibers) bore, although other and 1:7 inches twist rates are available as well.
Recoil
The M16 uses a "straight-line" recoil design, where the recoil spring is located in the stock directly behind the action,
and serves the dual function of operating spring and recoil buffer.
The stock being in line with the bore also reduces muzzle rise, especially during automatic fire. Because recoil does not significantly shift the point of aim, faster follow-up shots are possible and user fatigue is reduced. In addition, current model M16 flash-suppressors also act as compensators to reduce recoil further.
Notes:
Free recoil
Free recoil is a vernacular term or jargon for recoil energy of a firearm not supported from behind. Free recoil denotes the translational kinetic energy (''Et'') imparted to the shooter of a small arm when discharged and is expressed in joules ( ...
is calculated by using the rifle weight, bullet weight, muzzle velocity, and charge weight.
It is that which would be measured if the rifle were fired suspended from strings, free to recoil.
A rifle's perceived recoil is also dependent on many other factors which are not readily quantified.
Sights
![M16 upper right](https://upload.wikimedia.org/wikipedia/commons/6/61/M16_upper_right.jpg)
The M16's most distinctive ergonomic feature is the carrying handle and rear sight assembly on top of the receiver. This is a by-product of the
original AR-10 design, where the carrying handle contained a rear sight that could be set for specific range settings and also served to protect the charging handle.
The M16 carry handle also provided mounting groove interfaces and a hole at the bottom of the handle groove for mounting a Colt 3×20
telescopic sight
A telescopic sight, commonly called a scope informally, is an optical sighting device based on a refracting telescope. It is equipped with some form of a referencing pattern – known as a ''reticle'' – mounted in a focally appropriate po ...
featuring a
Bullet Drop Compensation
A telescopic sight, commonly called a scope informally, is an optical sighting device based on a refracting telescope. It is equipped with some form of a referencing pattern – known as a ''reticle'' – mounted in a focally appropriate po ...
elevation adjustment knob for ranges from . This concurs with the pre-M16A2 maximum effective range of .
The Colt 3×20 telescopic sight was factory adjusted to be parallax-free at . In Delft, the Netherlands
Artillerie-Inrichtingen
Artillerie-Inrichtingen was a Dutch state-owned artillery, small arms, and munitions company which also produced machine tools and was founded in 1679 in Delft, Netherlands. The company was split in 1973 with its defense related businesses becomin ...
produced a roughly similar 3×25 telescopic sight for the carrying handle mounting interfaces.
The M16 elevated iron sight line has a sight radius.
As the M16 series rear sight, front sight and sighting in targets designs were modified over time and non-iron sight (optical) aiming devices and new service ammunition were introduced zeroing procedures changed.
The standard pre-M16A2 "Daylight Sight System" uses an
AR-15-style L-type flip, two
aperture rear sight featuring two combat settings: short-range and long-range , marked 'L'.
The pre-M16A2 "Daylight Sight System" short-range and long-range zeros are with M193 ammunition. The rear sight features a windage drum that can be adjusted during zeroing with about 1
MOA increments. The front sight is a tapered round post of approximately diameter adjustable during zeroing in about 1
MOA increments. A cartridge or tool is required to (re)zero the sight line.
An alternative pre-M16A2 "Low Light Level Sight System", includes a front sight post with a weak light source provided by
tritium radioluminescence
Tritium radioluminescence is the use of gaseous tritium, a radioactive isotope of hydrogen, to create visible light. Tritium emits electrons through beta decay and, when they interact with a phosphor material, light is emitted through the proces ...
in an embedded small glass vial and a two aperture rear sight consisting of a diameter aperture marked 'L' intended for normal use out to and a diameter large aperture for night firing. Regulation stipulates the radioluminescant front sight post must be replaced if more than 144 months (12 years) elapsed after manufacture. The "Low Light Level Sight System" elevation and windage adjustment increments are somewhat coarser compared to the "Daylight Sight System".
With the advent of the M16A2, a less simple fully adjustable rear sight was added, allowing the rear sight to be dialed in with an elevation wheel for specific range settings between in 100 m increments and to allow windage adjustments with a windage knob without the need of a cartridge or tool. The unmarked approximately diameter aperture rear sight is for normal firing situations, zeroing and with the elevation knob for target distances up to 800 meters. The downsides of relatively small rear sight apertures are less light transmission through the aperture and a reduced field of view. A new larger approximately diameter aperture, marked '0-2' and featuring a windage setting index mark, offers a larger field of view during battle conditions and is used as a
ghost ring for quick target engagement and during limited visibility. When flipped down, the engraved windage mark on top of the '0-2' aperture ring shows the dialed in windage setting on a windage scale at the rear of the rear sight assembly. When the normal use rear aperture sight is zeroed at 300 m with SS109/M855 ammunition, first used in the M16A2, the '0-2' rear sight will be zeroed for 200 m.
The front sight post was widened to approximately diameter and became square and became adjustable during zeroing in about 1.2 MOA increments.
The M16A4 omitted the carrying handle and rear sight assembly on top of the receiver. Instead, it features a MIL-STD-1913
Picatinny rail
The Picatinny rail ( or ), or Pic rail for short, also known as a MIL-STD-1913 rail, 1913 rail or STANAG 2324 rail (cancelled), is a military standard rail interface system that provides a mounting platform for firearm accessories. It was o ...
ed flat-top upper receiver for mounting various optical sighting devices or a new detachable carrying handle and M16A2-style rear sight assembly.
The current U.S. Army and Air Force issue M4(A1) Carbine comes with the
M68 Close Combat Optic and Back-up Iron Sight. The U.S. Marine Corps uses the 4×32
ACOG Rifle Combat Optic and the U.S. Navy uses the
EOTech
EOTECH is an American company that designs, manufactures, and markets electro-optic and night vision products and systems. The company is headquartered in Plymouth, Michigan. They produce holographic weapon sights for small arms that have bee ...
Holographic Weapon Sight
A holographic weapon sight or holographic diffraction sight is a non- magnifying gunsight that allows the user to look through a glass optical window and see a holographic reticle image superimposed at a distance on the field of view. The hologram ...
.
Range and accuracy
The M16 rifle is considered to be very accurate for a service rifle.
Its light recoil, high-velocity and flat trajectory allow shooters to take head shots out to 300 meters.
[Sweeney, Patrick. ''Gun Digest Book of the AR-15'', Volume 2 ] Newer M16s use the newer M855 cartridge increasing their effective range to 600 meters.
They are more accurate than their predecessors and are capable of shooting 1–3-inch groups at 100 yards.
[Avtomat Kalashnikov](_blank)
. Alpharubicon.com. Retrieved on 3 April 2012. "In Fallujah,
Iraq
Iraq,; ku, عێراق, translit=Êraq officially the Republic of Iraq, '; ku, کۆماری عێراق, translit=Komarî Êraq is a country in Western Asia. It is bordered by Turkey to Iraq–Turkey border, the north, Iran to Iran–Iraq ...
Marines with ACOG-equipped M16A4s created a stir by taking so many head shots that until the wounds were closely examined, some observers thought the insurgents had been executed." The newest M855A1 EPR cartridge is even more accurate and during testing "...has shown that, on average, 95 percent of the rounds will hit within an 8 × 8-inch (20.3 × 20.3 cm) target at 600 meters."
Note *: The effective range of a firearm is the maximum distance at which a weapon may be expected to be accurate and achieve the desired effect.
Note **: The horizontal range is the distance traveled by a bullet, fired from the rifle at a height of 1.6 meters and 0° elevation, until the bullet hits the ground.
Note ***: The lethal range is the maximum range of a small-arms projectile, while still maintaining the minimum energy required to put unprotected personnel out of action, which is generally believed to be 15 kilogram-meters (147 J / 108 ft.lbf). This is the equivalent of the muzzle energy of a .22LR handgun.
Note ****: The maximum range of a small-arms projectile is attained at about 30° elevation. This maximum range is only of safety interest, not for combat firing.
Terminal ballistics
The
5.56×45 mm cartridge had several advantages over the
7.62×51 mm NATO round used in the
M14 rifle. It enabled each soldier to carry more ammunition and was easier to control during automatic or burst fire.
The 5.56×45 mm NATO cartridge can also produce massive wounding effects when the bullet impacts at high speed and yaws ("tumbles") in tissue leading to fragmentation and rapid transfer of energy.
The original ammunition for the M16 was the 55-grain M193 cartridge. When fired from a barrel at ranges of up to , the thin-jacketed lead-cored round traveled fast enough (above ) that the force of striking a human body would cause the round to yaw (or tumble) and fragment into about a dozen pieces of various sizes thus created wounds that were out of proportion to its caliber.
These wounds were so devastating that many considered the M16 to be an inhumane weapon.
As the 5.56 mm round's velocity decreases, so does the number of fragments that it produces.
The 5.56 mm round does not normally fragment at distances beyond 200 meters or at velocities below 2500 ft/s, and its lethality becomes largely dependent on shot placement.
With the development of the M16A2, the new 62-grain M855 cartridge was adopted in 1983. The heavier bullet had more energy and was made with a steel core to penetrate Soviet
body armor
Body armor, also known as body armour, personal armor or armour, or a suit or coat of armor, is protective clothing designed to absorb or deflect physical attacks. Historically used to protect military personnel, today it is also used by variou ...
. However, this caused less fragmentation on impact and reduced effects against targets without armor, both of which lessened kinetic energy transfer and wounding ability.
Some soldiers and Marines coped with this through training, with requirements to shoot vital areas three times to guarantee killing the target.
However, there have been repeated and consistent reports of the M855's inability to wound effectively (i.e., fragment) when fired from the short barreled M4 carbine (even at close ranges).
The M4's 14.5-in. barrel length reduces muzzle velocity to about 2900 ft/s.
This reduced wounding ability is one reason that, despite the Army's transition to short-barrel M4s, the Marine Corps has decided to continue using the M16A4 with its 20-inch barrel as the 5.56×45 mm M855 is largely dependent upon high velocity in order to wound effectively.
In 2003, the U.S. Army contended that the lack of lethality of the 5.56×45 mm was more a matter of perception than fact.
With good shot placement to the head and chest, the target was usually defeated without issue.
The majority of failures were the result of hitting the target in non-vital areas such as extremities.
However, a minority of failures occurred in spite of multiple hits to the chest.
In 2006, a study found that 20% of soldiers using the M4 Carbine wanted more lethality or stopping power.
In June 2010, the U.S. Army announced it began shipping its new 5.56 mm, lead-free, M855A1 Enhanced Performance Round to active combat zones.
This upgrade is designed to maximize performance of the 5.56×45 mm round, to extend range, improve accuracy, increase penetration and to consistently fragment in soft-tissue when fired from not only standard length M16s, but also the short-barreled M4 carbines.
The U.S. Army has been impressed with the new M855A1 EPR round. A 7.62 NATO M80A1 EPR variant was also developed.
Magazines
![Improved M16 Magazine Follower](https://upload.wikimedia.org/wikipedia/commons/d/df/Improved_M16_Magazine_Follower.jpg)
The M16's magazine was meant to be a lightweight, disposable item.
As such, it is made of pressed/stamped aluminum and was not designed to be durable.
The M16 originally used a 20-round magazine which was later replaced by a bent 30-round design. As a result, the magazine follower tends to rock or tilt, causing malfunctions.
Many non-U.S. and commercial magazines have been developed to effectively mitigate these shortcomings (e.g., H&K's all-stainless-steel magazine,
Magpul's polymer P-MAG, etc.).
Production of the 30-round magazine started late 1967 but did not fully replace the 20-round magazine until the mid-1970s.
Standard USGI aluminum 30-round M16 magazines weigh empty and are long.
The newer plastic magazines are about a half-inch longer. The newer steel magazines are about 0.5-inch longer and four ounces heavier. The M16's magazine has become the unofficial
NATO
The North Atlantic Treaty Organization (NATO, ; french: Organisation du traité de l'Atlantique nord, ), also called the North Atlantic Alliance, is an intergovernmental military alliance between 30 member states – 28 European and two No ...
STANAG magazine and is currently used by many Western nations, in numerous weapon systems.
In 2009, the U.S. Military began fielding an "improved magazine" identified by a tan-colored follower.
"The new follower incorporates an extended rear leg and modified bullet protrusion for improved round stacking and orientation. The self-leveling/anti-tilt follower minimizes jamming while a wider spring coil profile creates even force distribution. The performance gains have not added weight or cost to the magazines."
In July 2016, the U.S. Army introduced another improvement, the new Enhanced Performance Magazine, which it says will result in a 300% increase in reliability in the M4 Carbine. Developed by the
United States Army Armament Research, Development and Engineering Center and the
Army Research Laboratory in 2013, it is tan colored with blue follower to distinguish it from earlier, incompatible magazines.
Muzzle devices
Most M16 rifles have a barrel threaded in 1⁄2-28" threads to incorporate the use of a muzzle device such as a
flash suppressor or
sound suppressor.
The initial flash suppressor design had three tines or prongs and was designed to preserve the shooter's night vision by disrupting the flash. Unfortunately it was prone to breakage and getting entangled in vegetation. The design was later changed to close the end to avoid this and became known as the "A1" or "bird cage" flash suppressor on the M16A1. Eventually on the M16A2 version of the rifle, the bottom port was closed to reduce muzzle climb and prevent dust from rising when the rifle was fired in the prone position.
For these reasons, the U.S. military declared the A2 flash suppressor as a compensator or a
muzzle brake; but it is more commonly known as the "GI" or "A2" flash suppressor.
The M16's
Vortex Flash Hider weighs 3 ounces, is 2.25 inches long, and does not require a lock washer to attach to barrel.
It was developed in 1984, and is one of the earliest privately designed muzzle devices. The U.S. military uses the Vortex Flash Hider on
M4 carbine
The M4 carbine (officially Carbine, Caliber 5.56 mm, M4) is a 5.56×45mm NATO, gas-operated, magazine-fed carbine developed in the United States during the 1980s. It is a shortened version of the M16A2 assault rifle.
The M4 is extensively ...
s and M16 rifles. A version of the Vortex has been adopted by the Canadian Military for the Colt Canada C8 CQB rifle. Other flash suppressors developed for the M16 include the Phantom Flash Suppressor by Yankee Hill Machine (YHM) and the KX-3 by
Noveske Rifleworks.
The threaded barrel allows sound suppressors with the same thread pattern to be installed directly to the barrel; however this can result in complications such as being unable to remove the suppressor from the barrel due to repeated firing on full auto or three-round burst.
A number of suppressor manufacturers have designed "direct-connect" sound suppressors which can be installed over an existing M16's flash suppressor as opposed to using the barrel's threads.
Grenade launchers and shotguns
![Loading M203 40 mm grenade launcher attached to an M16 rifle](https://upload.wikimedia.org/wikipedia/commons/1/1a/Loading_M203_40_mm_grenade_launcher_attached_to_an_M16_rifle.jpg)
All current M16 type rifles can mount under-barrel 40 mm grenade-launchers, such as the
M203 and
M320. Both use the same
40×46mm LV grenades as the older, stand-alone
M79 grenade launcher
The M79 grenade launcher is a single-shot, shoulder-fired, break-action grenade launcher that fires a 40×46mm grenade, which uses what the US Army calls the High-Low Propulsion System to keep recoil forces low, and first appeared during the V ...
. The M16 can also mount under-barrel 12 gauge shotguns such as
KAC Masterkey
The Masterkey is a door breaching shotgun system manufactured by Knight's Armament Company.
The Masterkey project was initiated during the 1980s to provide assault rifles with a potent built-in door breaching tool. Individual soldiers were ofte ...
or the
M26 Modular Accessory Shotgun System.
Riot Control Launcher
![M234](https://upload.wikimedia.org/wikipedia/commons/0/00/M234.png)
The
M234 Riot Control Launcher is an M16-series rifle attachment firing an
M755 blank round. The M234 mounts on the muzzle, bayonet lug, and front sight post of the M16. It fires either the M734 64 mm Kinetic Riot Control or the M742 64 mm CSI Riot Control Ring Airfoil Projectiles. The latter produces a 4 to 5-foot
tear gas
Tear gas, also known as a lachrymator agent or lachrymator (), sometimes colloquially known as "mace" after the early commercial aerosol, is a chemical weapon that stimulates the nerves of the lacrimal gland in the eye to produce tears. In ad ...
cloud on impact. The main advantage to using
Ring Airfoil Projectile
The M234 Riot Control Launcher is an M16 series rifle or M4 series carbine attachment firing a M755 Grenade round. The M234 mounts on the muzzle, bayonet lug and front sight post of the M16. It fires either the M734 64 mm Kinetic Riot Cont ...
s is that their design does not allow them be thrown back by rioters with any real effect. The M234 is no longer used by U.S. forces. It has been replaced by the
M203 40 mm grenade launcher and
nonlethal
Non-lethal weapons, also called nonlethal weapons, less-lethal weapons, less-than-lethal weapons, non-deadly weapons, compliance weapons, or pain-inducing weapons are weapons intended to be less likely to kill a living target than conventional ...
ammunition.
Bayonet
The M16 is 44.25 inches (1124 mm) long with an
M7 bayonet attached.
The M7 bayonet is based on earlier designs such as the
M4,
M5, &
M6 bayonets, all of which are direct descendants of the
M3 Fighting Knife and have spear-point blade with a half sharpened secondary edge. The newer
M9 bayonet has a clip-point blade with saw teeth along the spine, and can be used as a multi-purpose knife and wire-cutter when combined with its scabbard. The current USMC
OKC-3S bayonet bears a resemblance to the Marines' iconic
Ka-Bar fighting knife with serrations near the handle.
Bipod
For use as an ad-hoc automatic rifle, the M16 and M16A1 could be equipped with the XM3 bipod, later standardized as the ''Bipod, M3'' (1966) and ''Rifle Bipod M3'' (1983). Weighing only 0.6 lb, the simple and non-adjustable bipod clamps to the barrel of the rifle to allow for supported fire.
The M3 bipod continues to be referenced in at least one official manual as late as 1985, where it is stated that one of the most stable firing positions is "the prone biped
icsupported for automatic fire."
NATO standards
In March 1970, the U.S. recommended that all
NATO
The North Atlantic Treaty Organization (NATO, ; french: Organisation du traité de l'Atlantique nord, ), also called the North Atlantic Alliance, is an intergovernmental military alliance between 30 member states – 28 European and two No ...
forces adopt the
5.56×45 mm cartridge.
This shift represented a change in the philosophy of the military's long-held position about caliber size. By the mid 1970s, other armies were looking at M16-style weapons. A NATO standardization effort soon started and tests of various rounds were carried out starting in 1977.
The U.S. offered the 5.56×45 mm M193 round, but there were concerns about its penetration in the face of the wider introduction of
body armor
Body armor, also known as body armour, personal armor or armour, or a suit or coat of armor, is protective clothing designed to absorb or deflect physical attacks. Historically used to protect military personnel, today it is also used by variou ...
.
In the end the Belgian 5.56×45 mm SS109 round was chosen (
STANAG 4172) in October 1980.
The SS109 round was based on the U.S. cartridge but included a new stronger, heavier, 62 grain bullet design, with better long range performance and improved penetration (specifically, to consistently penetrate the side of a steel helmet at 600 meters).
Due to its design and lower muzzle velocity (about 3110 ft/s)
the Belgian SS109 round is considered more humane because it is less likely to fragment than the U.S. M193 round.
The NATO 5.56×45 mm standard ammunition produced for U.S. forces is designated
M855.
In October 1980, shortly after NATO accepted the
5.56×45 mm NATO rifle cartridge. Draft Standardization Agreement 4179 (
STANAG 4179
In NATO, a standardization agreement (STANAG, redundantly: STANAG agreement) defines processes, procedures, terms, and conditions for common military or technical procedures or equipment between the member countries of the alliance. Each NATO st ...
) was proposed to allow NATO members to easily share rifle
ammunition
Ammunition (informally ammo) is the material fired, scattered, dropped, or detonated from any weapon or weapon system. Ammunition is both expendable weapons (e.g., bombs, missiles, grenades, land mines) and the component parts of other weap ...
and magazines down to the individual soldier level. The magazine chosen to become the ''
STANAG magazine'' was originally designed for the U.S. M16 rifle. Many NATO member nations, but not all, subsequently developed or purchased rifles with the ability to accept this type of magazine. However, the standard was never ratified and remains a 'Draft STANAG'.
All current M16 type rifles are designed to fire
STANAG 22 mm rifle grenades from their integral flash hiders without the use of an adapter. These 22 mm grenade types range from anti-tank rounds to simple finned tubes with a fragmentation hand grenade attached to the end. They come in the "standard" type which are propelled by a blank cartridge inserted into the chamber of the rifle. They also come in the "bullet trap" and "shoot through" types, as their names imply, they use live ammunition. The U.S. military does not generally use rifle grenades; however, they are used by other nations.
The
NATO Accessory Rail
The NATO Accessory Rail (NAR), defined by NATO Standardization Agreement (STANAG) 4694, is a rail interface system standard for mounting accessory equipments such as telescopic sights, tactical lights, laser aiming modules, night vision devices ...
STANAG 4694, or
Picatinny rail
The Picatinny rail ( or ), or Pic rail for short, also known as a MIL-STD-1913 rail, 1913 rail or STANAG 2324 rail (cancelled), is a military standard rail interface system that provides a mounting platform for firearm accessories. It was o ...
STANAG 2324, or a "Tactical Rail" is a bracket used on M16 type rifles to provide a standardized mounting platform. The rail comprises a series of ridges with a T-shaped cross-section interspersed with flat "spacing slots". Scopes are mounted either by sliding them on from one end or the other; by means of a "rail-grabber" which is clamped to the rail with bolts, thumbscrews or levers; or onto the slots between the raised sections. The rail was originally for scopes. However, once established, the use of the system was expanded to other accessories, such as tactical lights, laser aiming modules, night vision devices,
reflex sight
A reflector sight or reflex sight is an optical sight that allows the user to look through a partially reflecting glass element and see an illuminated projection of an aiming point or some other image superimposed on the field of view. These sigh ...
s, foregrips, bipods, and bayonets.
Currently, the M16 is in use by 15 NATO countries and more than 80 countries worldwide.
Variants
M16
![Armamento - Museo de Armas de la Nación 05](https://upload.wikimedia.org/wikipedia/commons/7/74/Armamento_-_Museo_de_Armas_de_la_Naci%C3%B3n_05.JPG)
This was the first M16 variant adopted operationally, originally by the U.S. Air Force. It was equipped with triangular handguards, buttstocks without a compartment for the storage of a cleaning kit,
a three-pronged "duckbill" flash suppressor designed to preserve the shooter's night vision by disrupting the flash, full auto, and no
forward assist. The M16 has a safe/semi/auto selective fire trigger group. Bolt carriers were originally chrome plated and slick-sided, lacking forward assist notches. Later, the chrome plated carriers were dropped in favor of Army issued notched and
parkerized carriers though the interior portion of the bolt carrier is still chrome-lined.
The barrel
rifling
In firearms, rifling is machining helical grooves into the internal (bore) surface of a gun's barrel for the purpose of exerting torque and thus imparting a spin to a projectile around its longitudinal axis during shooting to stabilize the pro ...
had a 1:12 (305 mm)
twist rate to adequately stabilize M193 ball and M196 tracer ammunition.
The Air Force continued to operate these weapons until around 2001, at which time the Air Force converted all of its M16s to the M16A2 configuration.
The M16 was also adopted by the
British SAS
The Special Air Service (SAS) is a special forces unit of the British Army. It was founded as a regiment in 1941 by David Stirling and in 1950, it was reconstituted as a corps. The unit specialises in a number of roles including counter-terr ...
, who used it during the
Falklands War
The Falklands War ( es, link=no, Guerra de las Malvinas) was a ten-week undeclared war between Argentina and the United Kingdom in 1982 over two British dependent territories in the South Atlantic: the Falkland Islands and its territorial de ...
.
XM16E1 and M16A1 (Colt Model 603)
![M16A1 brimob](https://upload.wikimedia.org/wikipedia/commons/6/6b/M16A1_brimob.jpg)
The U.S. Army XM16E1 was essentially the same weapon as the M16 with the addition of a
forward assist and corresponding notches in the bolt carrier. The M16A1 was the finalized production model in 1967 and was produced until 1982.
To address issues raised by the XM16E1's testing cycle, a closed, birdcage symmetric
flash suppressor with open side slots to the top, bottom, left and right replaced the XM16E1's three-pronged flash suppressor which caught on twigs and leaves from 1967 onwards. Various other changes were made after numerous problems in the field. Cleaning kits were developed and issued while barrels with chrome-plated chambers and later fully lined bores were introduced. A small storage compartment inside the stock was introduced. The buttstock storage compartment is often used for storing a basic cleaning kit.
With these and other changes, the malfunction rate slowly declined and new soldiers were generally unfamiliar with early problems. A rib was built into the side of the receiver on the XM16E1 to help prevent accidentally pressing the magazine release button while closing the ejection port cover. This rib was later extended on production M16A1s to help in preventing the magazine release from inadvertently being pressed. The hole in the bolt that accepts the cam pin was crimped inward on one side, in such a way that the cam pin may not be inserted with the bolt installed backwards, which would cause failures to eject until corrected. The M16A1 saw limited use in training capacities until the early 2000s, but is no longer in active service with the U.S., although is still standard issue in many world armies.
M16A2
![M16a2m203 afmil](https://upload.wikimedia.org/wikipedia/commons/e/ee/M16a2m203_afmil.jpg)
The development of the M16A2 rifle was originally requested by the
United States Marine Corps
The United States Marine Corps (USMC), also referred to as the United States Marines, is the maritime land force service branch of the United States Armed Forces responsible for conducting expeditionary and amphibious operations through combi ...
in 1979 as a result of combat experience in Vietnam with the M16A1. It was officially adopted by the Department of Defense as the "Rifle, 5.56 mm, M16A2" in 1983. The Marines were the first branch of the U.S. Armed Forces to adopt it, in the early/mid-1980s, with the
United States Army
The United States Army (USA) is the land service branch of the United States Armed Forces. It is one of the eight U.S. uniformed services, and is designated as the Army of the United States in the U.S. Constitution.Article II, section 2, cla ...
following suit in 1986.
Modifications to the M16A2 were extensive. In addition to the then new
STANAG 4172
5.56×45mm NATO
The 5.56×45mm NATO (official NATO nomenclature 5.56 NATO, but often pronounced "five-five-six") is a rimless bottlenecked intermediate cartridge family developed in the late 1970s in Belgium by FN Herstal. It consists of the SS109, L110, and ...
chambering and its accompanying rifling, the barrel was made with a greater thickness in front of the front sight post, to resist bending in the field and to allow a longer period of sustained fire without overheating. The rest of the barrel was maintained at the original thickness to enable the
M203 grenade launcher
The M203 is a single-shot 40 mm under-barrel grenade launcher designed to attach to a rifle. It uses the same rounds as the older stand-alone M79 break-action grenade launcher, which utilizes the high-low propulsion system to keep recoil force ...
to be attached.
The barrel
rifling
In firearms, rifling is machining helical grooves into the internal (bore) surface of a gun's barrel for the purpose of exerting torque and thus imparting a spin to a projectile around its longitudinal axis during shooting to stabilize the pro ...
was revised to a faster 1:7 (178 mm)
twist rate to adequately stabilize the new 5.56×45 mm NATO SS109/M855 ball and L110/M856 tracer ammunition. The heavier longer SS109/M855 bullet reduced
muzzle velocity
Muzzle velocity is the speed of a projectile (bullet, pellet, slug, ball/shots or shell) with respect to the muzzle at the moment it leaves the end of a gun's barrel (i.e. the muzzle). Firearm muzzle velocities range from approximately to i ...
from , to about .
A new adjustable rear sight was added, allowing the rear sight to be dialed in for specific range settings between 300 and 800 meters to take full advantage of the ballistic characteristics of the SS109/M855 rounds and to allow windage adjustments without the need of a tool or cartridge.
The flash suppressor was again modified, this time to be closed on the bottom, so the new birdcage-type muzzle device would not kick up dirt or snow when being fired from the prone position, and additionally act as an asymmetric
recoil compensator
A muzzle brake or recoil compensator is a device connected to, or a feature integral to the construction of, the muzzle or barrel of a firearm or cannon that is intended to redirect a portion of propellant gases to counter recoil and unwanted ...
to reduce
muzzle climb
Muzzle rise, muzzle flip or muzzle climb refers to the tendency of a firearm's or airgun's Muzzle (firearms), muzzle (front end of the Gun barrel, barrel) to rise up after firing. It more specifically refers to the seemingly unpredictable "jump" ...
.
A spent case deflector was incorporated into the upper receiver immediately behind the ejection port to prevent (hot) cartridge cases from striking left-handed users.
The action was also modified, replacing the fully automatic setting with a three-round burst setting.
When using a fully automatic weapon, inexperienced troops often hold down the trigger and "spray" when under fire. The U.S. Army concluded that three-shot groups provide an optimum combination of ammunition conservation, accuracy, and firepower. The USMC has retired the M16A2 in favor of the newer M16A4; a few M16A2s remain in service with the
U.S. Army Reserve and
National Guard,
Air Force
An air force – in the broadest sense – is the national military branch that primarily conducts aerial warfare. More specifically, it is the branch of a nation's armed services that is responsible for aerial warfare as distinct from an a ...
,
Navy
A navy, naval force, or maritime force is the branch of a nation's armed forces principally designated for naval warfare, naval and amphibious warfare; namely, lake-borne, riverine, littoral zone, littoral, or ocean-borne combat operations and ...
and
Coast Guard.
The handguard was modified from the original triangular shape to a round one, which better fit smaller hands and could be fitted to older models of the M16. The new handguards were also symmetrical so armories need not separate left- and right-hand spares. The handguard retention ring was tapered to make it easier to install and uninstall the handguards.
The new buttstock became ten times stronger than the original due to advances in polymer technology since the early 1960s. Original M16 stocks were made from cellulose-impregnated phenolic resin; the newer M16A2 stocks were engineered from DuPont
Zytel
Zytel is a trademark owned by DuPont and used for a number of different high strength, abrasion and impact resistant thermoplastic polyamide formulations of the family more commonly known as nylon. The Zytel product line is based mostly on nylon 66 ...
glass-filled thermoset polymers and became a replacement part for the preceding M16A1. The new buttstock was lengthened by and included a fully textured polymer buttplate for better grip on the shoulder, and retained a panel for accessing a small compartment inside the stock, often used for storing a basic cleaning kit.
A notch for the middle finger was added to the pistol grip as well as more texture to enhance the grip. The new pistol grips were engineered from Zytel glass-filled thermoset polymers. The M16A2 pistol grip became a replacement part for the preceding M16A1.
The standard Model 645 M16A2 has a safe/semi/three-round burst selective fire trigger group. It became standard issue for the U.S. Marine Corps and Army.
There is also a safe/semi/three-round burst/automatic selective fire trigger group Model 708 version of M16A2 rifle named "M16A2 Enhanced", used by some militaries around the world.
M16A3
The M16A3 is a modified version of the M16A2 adopted in small numbers by the U.S. Navy
SEAL,
Seabee, and Security units.
It features the M16A1 selective fire trigger group providing "safe", "semi-automatic" and "fully automatic" modes. Otherwise it is externally similar to the M16A2.
M16A4
![The M16A4 Series 5](https://upload.wikimedia.org/wikipedia/commons/2/29/The_M16A4_Series_5.56mm_Rifle.jpg)
The M16A4 is the fourth generation of the M16 series. The iron sight/carrying handle assembly on the M16A2/M16A3 upper receiver, was replaced by a MIL-STD-1913 "
Picatinny rail
The Picatinny rail ( or ), or Pic rail for short, also known as a MIL-STD-1913 rail, 1913 rail or STANAG 2324 rail (cancelled), is a military standard rail interface system that provides a mounting platform for firearm accessories. It was o ...
ed" flat-top upper receiver for mounting aiming optics or a removable iron sight/carrying handle assembly. The M16A4 rear aperture sights integrated in the Picatinny rail mounted carry handle assembly are adjustable from 300 m (328 yd) up to 600 m (656 yd), where the further similar M16A2 iron sights line can reach up to 800 m (875 yd). The FN M16A4, using safe/semi/three-round burst selective fire, became standard issue for the U.S. Marine Corps.
Military issue rifles were also equipped with a full length quad
Knight's Armament Company
Knight's Armament Company (KAC) is an American firearms and firearms parts manufacturer, best known for producing the Rail Interface System (RIS) and the Rail Adapter System (RAS) grips for firearms use. They currently produce a variety of firea ...
M5 RAS Picatinny railed hand guard (that holds zero on the top rail), allowing vertical grips, lasers, tactical lights, and other accessories to be attached, coining the designation M16A4 MWS (or Modular Weapon System) in U.S. Army field manuals.
Colt also produces M16A4 models for international purchases:
* R0901 / RO901/
NSN 1005-01-383-2872 (Safe/Semi/Auto)
* R0905 / RO905 (Safe/Semi/Burst)
A study of significant changes to Marine M16A4 rifles released in February 2015 outlined several new features that could be added from inexpensive and available components. Those features included: a muzzle compensator in place of the flash suppressor to manage recoil and allow for faster follow-on shots, though at the cost of noise and flash signature and potential overpressure in close quarters; a heavier and/or
free-floating barrel
A free-floating barrel is a firearm design used in precision rifles, particularly match grade benchrest rifles, to accurize the weapon system.
With conventional rifles, the gun barrel rests in contact with the fore-end of the gunstock, sometim ...
to increase accuracy from 4.5 MOA (Minute(s) Of Angle) to potentially 2 MOA; changing the reticle on the
Rifle Combat Optic from chevron-shaped to a semi-circlar reticle with a dot at the center used in the
M27 IAR's Squad Day Optic so as not to obscure the target at long distance; using a trigger group with a more consistent pull force, even a reconsideration of the burst capability; and the addition of ambidextrous charging handles and bolt catch releases for easier use with left-handed shooters.
In 2014, Marine units were provided with a limited number of adjustable stocks in place of the traditional fixed stock for their M16A4s to issue to smaller Marines who would have trouble comfortably reaching the trigger when wearing body armor. The adjustable stocks were added as a standard authorized accessory, meaning units can use operations and maintenance funds to purchase more if needed.
The Marine Corps had long maintained the full-length M16 as their standard infantry rifle, but in October 2015 the switch to the M4 carbine was approved as the standard-issue weapon, giving Marine infantry a smaller and more compact weapon. Enough M4s were already in the inventory to re-equip all necessary units by September 2016, and M16A4s were moved to support
and non-infantry Marines.
Summary of differences
Derivatives
Colt Commando (AKA: XM177 & GAU-5)
![CCTwithGAU-5](https://upload.wikimedia.org/wikipedia/commons/9/92/CCTwithGAU-5.jpg)
In Vietnam, some soldiers were issued a
carbine version of the M16 named
XM177
The Colt Automatic Rifle-15 or CAR-15 is a family of M16 rifle–based firearms marketed by Colt in the 1960s and early 1970s. However, the term "CAR-15" is most commonly associated with the Colt Commando (AKA: XM177); these select-fire carbine ...
. The XM177 had a shorter barrel and a telescoping stock, which made it substantially more compact. It also possessed a combination flash hider/sound moderator to reduce problems with muzzle flash and loud report. The Air Force's GAU-5/A (XM177) and the Army's XM177E1 variants differed over the latter's inclusion of a forward assist, although some GAU-5s do have the forward assist. The final Air Force GAU-5/A and Army XM177E2 had an barrel with a longer flash/sound suppressor. The lengthening of the barrel was to support the attachment of Colt's own
XM148 40 mm grenade launcher. These versions were also known as the Colt Commando model commonly referenced and marketed as the CAR-15. The variants were issued in limited numbers to special forces, helicopter crews, Air Force pilots, Air Force Security Police Military Working Dog (MWD) handlers, officers, radio operators, artillerymen, and troops other than front line riflemen. Some USAF GAU-5A/As were later equipped with even longer 1/12 rifled barrels as the two shorter versions were worn out. The barrel allowed the use of MILES gear and for bayonets to be used with the sub-machine guns (as the Air Force described them). By 1989, the Air Force started to replace the earlier barrels with 1/7 rifled models for use with the M855-round. The weapons were given the redesignation of GUU-5/P.
These were used by the British
Special Air Service
The Special Air Service (SAS) is a special forces unit of the British Army. It was founded as a regiment in 1941 by David Stirling and in 1950, it was reconstituted as a corps. The unit specialises in a number of roles including counter-terro ...
during the
Falklands War
The Falklands War ( es, link=no, Guerra de las Malvinas) was a ten-week undeclared war between Argentina and the United Kingdom in 1982 over two British dependent territories in the South Atlantic: the Falkland Islands and its territorial de ...
.
M4 carbine
![SCRange20034344940](https://upload.wikimedia.org/wikipedia/commons/8/86/SCRange20034344940.jpg)
The M4 carbine was developed from various outgrowths of these designs, including a number of -barreled A1 style carbines. The XM4 (Colt Model 720) started its trials in 1984, with a barrel of . The weapon became the M4 in 1991. Officially adopted as a replacement for the
M3 "Grease Gun" (and the
Beretta M9 and M16A2 for select troops) in 1994, it was used with great success in the Balkans and in more recent conflicts, including the
Afghanistan
Afghanistan, officially the Islamic Emirate of Afghanistan,; prs, امارت اسلامی افغانستان is a landlocked country located at the crossroads of Central Asia and South Asia. Referred to as the Heart of Asia, it is bordere ...
and
Iraq
Iraq,; ku, عێراق, translit=Êraq officially the Republic of Iraq, '; ku, کۆماری عێراق, translit=Komarî Êraq is a country in Western Asia. It is bordered by Turkey to Iraq–Turkey border, the north, Iran to Iran–Iraq ...
theaters. The M4 carbine has a three-round
burst
Burst may refer to:
*Burst mode (disambiguation), a mode of operation where events occur in rapid succession
**Burst transmission, a term in telecommunications
**Burst switching, a feature of some packet-switched networks
** Bursting, a signaling m ...
firing mode, while the M4A1 carbine has a
fully automatic firing mode. Both have a
Picatinny rail
The Picatinny rail ( or ), or Pic rail for short, also known as a MIL-STD-1913 rail, 1913 rail or STANAG 2324 rail (cancelled), is a military standard rail interface system that provides a mounting platform for firearm accessories. It was o ...
on the upper receiver, allowing the carry handle/rear sight assembly to be replaced with other sighting devices.
M4 Commando
Colt also returned to the original "
Commando" idea, with its Model 733, essentially a modernized XM177E2 with many of the features introduced on the M16A2.
Diemaco C7 and C8
![Canadian C7A2 Rifle](https://upload.wikimedia.org/wikipedia/commons/9/96/Canadian_C7A2_Rifle.JPG)
The
Diemaco C7 and C8 are updated variants of the M16 developed and used by the
Canadian Forces
}
The Canadian Armed Forces (CAF; french: Forces armées canadiennes, ''FAC'') are the unified military forces of Canada, including sea, land, and air elements referred to as the Royal Canadian Navy, Canadian Army, and Royal Canadian Air Force.
...
and are now manufactured by
Colt Canada. The C7 is a further development of the experimental M16A1E1. Like earlier M16s, it can be fired in either semi-automatic or automatic mode, instead of the burst function selected for the M16A2. The C7 also features the structural strengthening, improved handguards, and longer stock developed for the M16A2. Diemaco changed the trapdoor in the buttstock to make it easier to access and a spacer of is available to adjust stock length to user preference. The most easily noticeable external difference between American M16A2s and Diemaco C7s is the retention of the A1 style rear sights. Not easily apparent is Diemaco's use of hammer-forged barrels. The Canadians originally desired to use a heavy barrel profile instead.
The C7 has been developed to the C7A1, with a
Weaver rail
A Weaver rail mount is a system to connect telescopic sights (often via a scope mount) and other accessories to firearms and certain crossbows. It uses a pair of parallel rails and several slots perpendicular to these rails.
The later Picatinny ...
on the upper receiver for a C79 3.4×28 optical sight, and to the C7A2, with different furniture and internal improvements. The Diemaco produced Weaver rail on the original C7A1 variants does not meet the M1913 "Picatinny" standard, leading to some problems with mounting commercial sights. This is easily remedied with minor modification to the upper receiver or the sight itself. Since Diemaco's acquisition by Colt to form Colt Canada, all Canadian produced flattop upper receivers are machined to the M1913 standard.
The C8 is the carbine version of the C7. The C7 and C8 are also used by ''
Hærens Jegerkommando
Hærens Jegerkommando was a special forces unit of the Norwegian military. It was the armed forces competence centre for commando, airborne and counter terrorist duty in the Norwegian Army. Its headquarters were located 30 kilometres north of ...
'', ''
Marinejegerkommandoen'' and
FSK FSK may refer to:
* FSK (band), a German band
* Federal Counterintelligence Service, (Russian ') of Russia
* Fiskerton railway station, in England
* Forskolin, a diterpene
* Forsvarets Spesialkommando, a Norwegian special forces unit
* Fort Scott M ...
(Norway),
Denmark's Armed Forces (all branches), and the
Netherlands Armed Forces
The Netherlands Armed Forces ( nl, Nederlandse krijgsmacht) are the military services of the Kingdom of the Netherlands. The core of the armed forces consists of the four service branches: the Royal Netherlands Navy (), the Royal Netherlands ...
as its main infantry weapon. Following trials, variants became the weapon of choice of the British
SAS
SAS or Sas may refer to:
Arts, entertainment, and media
* ''SAS'' (novel series), a French book series by Gérard de Villiers
* ''Shimmer and Shine'', an American animated children's television series
* Southern All Stars, a Japanese rock ba ...
.
Mk 4 Mod 0
The Mk 4 Mod 0 was a variant of the M16A1 produced for the U.S. Navy SEALs during the Vietnam War and adopted in April 1970. It differed from the basic M16A1 primarily in being optimized for maritime operations and coming equipped with a sound suppressor. Most of the operating parts of the rifle were coated in
Kal-Guard, a hole of was drilled through the stock and buffer tube for drainage, and an O-ring was added to the end of the buffer assembly. The weapon could reportedly be carried to the depth of 200 feet (60 m) in water without damage. The initial Mk 2 Mod 0 Blast Suppressor was based on the U.S. Army's Human Engineering Lab's (HEL) M4 noise suppressor. The HEL M4 vented gas directly from the action, requiring a modified bolt carrier. A gas deflector was added to the charging handle to prevent gas from contacting the user. Thus, the HEL M4 suppressor was permanently mounted though it allowed normal semi-automatic and automatic operation. If the HEL M4 suppressor were removed, the weapon would have to be manually loaded after each single shot. On the other hand, the Mk 2 Mod 0 blast suppressor was considered an integral part of the Mk 4 Mod 0 rifle, but it would function normally if the suppressor were removed. The Mk 2 Mod 0 blast suppressor also drained water much more quickly and did not require any modification to the bolt carrier or to the charging handle. In the late 1970s, the Mk 2 Mod 0 blast suppressor was replaced by the Mk 2 blast suppressor made by Knight's Armament Company (KAC). The KAC suppressor can be fully submerged and water will drain out in less than eight seconds. It will operate without degradation even if the rifle is fired at the maximum rate of fire. The U.S. Army replaced the HEL M4 with the much simpler Studies in Operational Negation of Insurgency and Counter-Subversion (SIONICS) MAW-A1 noise and flash suppressor.
US Navy Mk 12 Special Purpose Rifle
![SPRCrane](https://upload.wikimedia.org/wikipedia/commons/3/3a/SPRCrane.jpg)
Developed to increase the effective range of soldiers in the designated marksman role, the U.S. Navy developed the Mark 12 Special Purpose Rifle (SPR). Configurations in service vary, but the core of the Mark 12 SPR is an 18" heavy barrel with muzzle brake and free float tube. This tube relieves pressure on the barrel caused by standard handguards and greatly increases the potential accuracy of the system. Also common are higher magnification optics ranging from the 6× power Trijicon ACOG to the Leupold Mark 4 Tactical rifle scopes. Firing Mark 262 Mod 0 ammunition with a 77gr Open tip Match bullet, the system has an official effective range of 600+ meters. However published reports of confirmed kills beyond 800 m from Iraq and Afghanistan were not uncommon.
M231 Firing Port Weapon (FPW)
![M231 1](https://upload.wikimedia.org/wikipedia/commons/5/5c/M231_1.svg)
The
M231 Firing Port Weapon (FPW) is an adapted version of the M16 assault rifle for firing from
ports on the
M2 Bradley. The infantry's normal M16s are too long for use in a "buttoned up" fighting vehicle, so the FPW was developed to provide a suitable weapon for this role.
Colt Model 655 and 656 "Sniper" variants
With the expanding
Vietnam War
The Vietnam War (also known by #Names, other names) was a conflict in Vietnam, Laos, and Cambodia from 1 November 1955 to the fall of Saigon on 30 April 1975. It was the second of the Indochina Wars and was officially fought between North Vie ...
, Colt developed two rifles of the M16 pattern for evaluation as possible light sniper or designated marksman rifles. The Colt Model 655 M16A1 Special High Profile was essentially a standard A1 rifle with a heavier barrel and a scope bracket that attached to the rifle's carry handle. The Colt Model 656 M16A1 Special Low Profile had a special upper receiver with no carrying handle. Instead, it had a low-profile iron sight adjustable for windage and a Weaver base for mounting a scope, a precursor to the Colt and Picatinny rails. It also had a hooded front iron sight in addition to the heavy barrel. Both rifles came standard with either a Leatherwood/Realist scope 3–9× Adjustable Ranging Telescope. Some of them were fitted with a Sionics noise and flash suppressor. Neither of these rifles were ever standardized.
These weapons can be seen in many ways to be predecessors of the U.S. Army's
SDM-R and the USMC's
SAM-R weapons.
Others
* The Chinese
Norinco CQ
The Type CQ is an unlicensed Chinese variant of the M16 rifle manufactured by Norinco. According to the Norinco website, the rifle is officially known as CQ 5.56.
It can be distinguished from other AR-15 and M-16 pattern rifles by its long, r ...
is an unlicensed derivative of the M16A1 made specifically for export, with the most obvious external differences being in its handguard and
revolver
A revolver (also called a wheel gun) is a repeating handgun that has at least one barrel and uses a revolving cylinder containing multiple chambers (each holding a single cartridge) for firing. Because most revolver models hold up to six roun ...
-style pistol grip.
** The ARMADA rifle (a copy of the Norinco CQ) and TRAILBLAZER carbine (a copy of the Norinco CQ Type A) are manufactured by S.A.M. – Shooter's Arms Manufacturing, a.k.a. Shooter's Arms Guns & Ammo Corporation, headquartered in
Metro Cebu,
Republic of the Philippines
The Philippines (; fil, Pilipinas, links=no), officially the Republic of the Philippines ( fil, Republika ng Pilipinas, links=no),
* bik, Republika kan Filipinas
* ceb, Republika sa Pilipinas
* cbk, República de Filipinas
* hil, Republ ...
.
** The S-5.56 rifle, a clone of the Type CQ, is manufactured by the
Defense Industries Organization of
Iran
Iran, officially the Islamic Republic of Iran, and also called Persia, is a country located in Western Asia. It is bordered by Iraq and Turkey to the west, by Azerbaijan and Armenia to the northwest, by the Caspian Sea and Turkmeni ...
. The rifle itself is offered in two variants: the S-5.56 A1 with a 19.9-inch barrel and 1:12 pitch rifling (1 turn in 305 mm), optimized for the use of the M193 Ball cartridge; and the S-5.56 A3 with a 20-inch barrel and a 1:7 pitch rifling (1 turn in 177, 8 mm), optimized for the use of the SS109 cartridge.
** The
KH-2002
The KH-2002 ''Khaybar'' ( fa, خیبر ) is an Iranian-designed assault rifle, derived from the DIO S 5.56 assault rifle (an unlicensed clone of the Chinese Norinco CQ, which in turn is an unlicensed copy of the American M16) and further develo ...
is an Iranian
bullpup
A bullpup firearm is one with its firing grip located in front of the Chamber (firearms), breech of the weapon, instead of behind it. This creates a weapon with a shorter overall length for a given barrel length, and one that is often lighter, ...
conversion of the locally produced S-5.56 rifle. Iran intends to replace the standard issue weapon of its armed forces with this rifle.
** The Terab rifle is a copy of the DIO S-5.56 manufactured by the
Military Industry Corporation
The Military Industry Corporation is the state-run defense corporation of Sudan. It is responsible for the production of a wide range of defense equipment, such as munitions, firearms, artillery etc.
History
The MIC was established by national d ...
of
Sudan
Sudan ( or ; ar, السودان, as-Sūdān, officially the Republic of the Sudan ( ar, جمهورية السودان, link=no, Jumhūriyyat as-Sūdān), is a country in Northeast Africa. It shares borders with the Central African Republic t ...
.
* The M16S1 is the M16A1 rifle made under license by
ST Kinetics in
Singapore
Singapore (), officially the Republic of Singapore, is a sovereign island country and city-state in maritime Southeast Asia. It lies about one degree of latitude () north of the equator, off the southern tip of the Malay Peninsula, borde ...
. It was the standard issue weapon of the Singapore Armed Forces. It is being replaced by the newer SAR 21 in most branches. It is, in the meantime, the standard issue weapon in the reserve forces.
* The
MSSR rifle is a sniper rifle developed by the
Philippine Marine Corps Scout Snipers that serves as their primary sniper weapon system.
* The
Special Operations Assault Rifle (SOAR)
The Special Operations Assault Rifle (SOAR) is an assault rifle manufactured by FERFRANS and designed as an improvement of the M4 carbine.
Details
The SOAR is a selective fire 5.56×45mm NATO assault rifle firing from either a closed rotating ...
assault carbine was developed by
Ferfrans
Ferfrans (stylized as FERFRANS) is an American firearms manufacturer based in Montclair, California. It was established in 1998 by Filipino-American brothers Ferdinand and Francis Sy. Ferfrans was derived from the brother's names, Ferdinand and Fr ...
based on the M16 rifle. It is used by the
Special Action Force
The Special Action Force (SAF) is the elite unit of the Philippine National Police founded by Fidel V. Ramos, later the twelfth president of the Philippines.
History
Formed on May 12, 1983, by the now-defunct Philippine Constabulary (PC) as th ...
of the
Philippine National Police
The Philippine National Police ( fil, Pambansang Pulisya ng Pilipinas, acronymed as PNP) is the armed national police force in the Philippines. Its national headquarters is located at Camp Crame in Bagong Lipunan ng Crame, Quezon City. Current ...
.
*
Taiwan
Taiwan, officially the Republic of China (ROC), is a country in East Asia, at the junction of the East and South China Seas in the northwestern Pacific Ocean, with the People's Republic of China (PRC) to the northwest, Japan to the nort ...
uses piston-driven M16-based weapons as their standard rifle. These include the
T65,
T86 and
T91 assault rifles.
* Ukraine has announced plans in January 2017 for
Ukroboronservis and
Aeroscraft
Worldwide Aeros Corp is an American manufacturer of airships based in Montebello, California. It was founded in 1993 by the current CEO and Chief Engineer, Igor Pasternak, who was born in Soviet Kazakhstan, raised in Soviet Ukraine, and moved to ...
to produce the M16 WAC47, an accurized M4 variation that uses standard 7.62×39 mm AK-47 magazines.
As of November 2019, no weapon manufactured as described in the above lines, has been produced.
*
New Zealand
New Zealand ( mi, Aotearoa ) is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and over 700 smaller islands. It is the sixth-largest island count ...
has adopted the
Lewis Machine and Tool Company's upgraded version of the M16 system to replace the
Steyr AUG
The Steyr AUG () is an Austrian bullpup assault rifle chambered for the 5.56×45mm NATO intermediate cartridge, designed in the 1960s by Steyr-Daimler-Puch, and now manufactured by Steyr Arms GmbH & Co KG.
It was adopted by the Austrian Arm ...
. This CQB16 rifle will be fielded in 2017 and is named
MARS-L (Modular Ambidextrous Rifle System-Light).
Production and users
![M16 operators of the world](https://upload.wikimedia.org/wikipedia/commons/d/dc/M16_operators_of_the_world.svg)
The M16 is the most commonly manufactured 5.56×45 mm rifle in the world. Currently, the M16 is in use by 15 NATO countries and more than 80 countries worldwide. Together, numerous companies in the United States, Canada, and China have produced more than 8,000,000 rifles of all variants. Approximately 90% are still in operation.
The M16 replaced both the
M14 rifle and
M2 carbine as standard infantry rifle of the U.S. armed forces. Although, the M14 continues to see limited service, mostly in
sniper
A sniper is a military/paramilitary marksman who engages targets from positions of concealment or at distances exceeding the target's detection capabilities. Snipers generally have specialized training and are equipped with high-precision r ...
,
designated marksman, and ceremonial roles.
Users
![Paskibra Pasukan 45](https://upload.wikimedia.org/wikipedia/commons/1/19/Paskibra_Pasukan_45.jpg)
* : Taliban use M16A2 and M16A4 rifles previously supplied for Afghan National Army. Also in use with the
Badri 313 Battalion
The Badri 313 Battalion ( ps, بدري ٣١٣ قطعه) is a unit of the Armed Forces of the Islamic Emirate of Afghanistan. The unit's name is closely associated with the Haqqani network, which has reportedly provided them with training. Elite Ta ...
.
*
*
* : Special Forces used the M16A1 in the
Falklands War
The Falklands War ( es, link=no, Guerra de las Malvinas) was a ten-week undeclared war between Argentina and the United Kingdom in 1982 over two British dependent territories in the South Atlantic: the Falkland Islands and its territorial de ...
and they currently use the M16A2 (by all Armed Forces).
* : M16A4, used by the special forces and State Border Service (DSX).
*
*
*
[Jane's Special Forces Recognition Guide, Ewen Southby-Tailyour (2005) p. 446.]
* :
M16A1/A4
*
*
* : Used by special forces in the final phase of the Araguaia guerilla war.
M16A2s used by
Brazilian Marine Corps )
, colors=Red and white
, colors_label=Colors
, march=
, mascot=
, battles = Invasion of Cayenne (1809) Banda Oriental Conquest (1816)War of Independence (1821–1824)Confederation of the Equator(1824)Cisplatine War(1825–1828)Ragamuffin War(183 ...
*
M16A2 is used by the
Royal Brunei Armed Forces as their main service rifle.
* : Burundian rebels
*
M16A1
*
* :
C7 and
C8 variants made by
Colt Canada are used by the
Canadian Forces
}
The Canadian Armed Forces (CAF; french: Forces armées canadiennes, ''FAC'') are the unified military forces of Canada, including sea, land, and air elements referred to as the Royal Canadian Navy, Canadian Army, and Royal Canadian Air Force.
...
.
[Miller, David (2001). ''The Illustrated Directory of 20th Century Guns''. Salamander Books Ltd. .]
*
*
M16A1 used by
Chilean Marine Corps
The Chilean Marine Corps ( es, Cuerpo de Infantería de Marina, CIM) is an entity of the Chilean Navy special forces which specializes in amphibious assaults.
History
The Marine Corps was born with the establishment of the first armed forces ...
.
*
*
:*
Democratic Forces for the Liberation of Rwanda
The Democratic Forces for the Liberation of Rwanda (french: Forces démocratiques de libération du Rwanda, FDLR) is an armed rebel group active in the eastern Democratic Republic of the Congo. As an ethnic Hutu group opposed to the ethnic Tuts ...
*
*
* :
*
*
* M16A2
*
*
*
M16A1/A2/A3/A4
* Ex-U.S. M16A1s
*
*
* : Used by counter-terrorism and special operations forces
*
*
*
M16A2
*
M16A2/A3/A4/M4/A2E M4 is used by the Special Forces of the
Hellenic Army
The Hellenic Army ( el, Ελληνικός Στρατός, Ellinikós Stratós, sometimes abbreviated as ΕΣ), formed in 1828, is the land force of Greece. The term ''Hellenic'' is the endogenous synonym for ''Greek''. The Hellenic Army is the ...
,
Hellenic Air Force and the
Hellenic Navy
The Hellenic Navy (HN; el, Πολεμικό Ναυτικό, Polemikó Naftikó, War Navy, abbreviated ΠΝ) is the naval force of Greece, part of the Hellenic Armed Forces. The modern Greek navy historically hails from the naval forces of vari ...
.
*
*
M16A1/M16A2.
*
*
*
[Gander, Terry J.; Hogg, Ian V. ''Jane's Infantry Weapons 1995/1996''. Jane's Information Group; 21 edition (May 1995). .] M16A1
*
*
*
*
*
*
*
* : M16A1 is used by
Western Army Infantry Regiment along with
Howa Type 89
The , referred to as the , is a Japanese assault rifle used by the Japan Self-Defense Forces, the Japan Coast Guard's Special Security Team units, and the Special Assault Team. It has never been exported outside Japan due to its strict Japanese ...
rifles.
*
M16A1/A
*
* M16A1/A2.
* :
*
M16A1
/A2/A4.
*
*
M16A2
* :
Lithuanian Armed Forces
The Lithuanian Armed Forces () are the military of Lithuania. The Lithuanian Armed Forces consist of the Lithuanian Land Forces, the Lithuanian Naval Force and the Lithuanian Air Force. In wartime, the Lithuanian State Border Guard Service (whi ...
*
Malaysian Armed Forces
The Malaysian Armed Forces (: MAF; ms, Angkatan Tentera Malaysia; Jawi: ), are the armed forces of Malaysia, consists of three branches; the Malaysian Army, Royal Malaysian Navy and the Royal Malaysian Air Force. The number of MAF active pers ...
,
Royal Johor Military Force,
Royal Malaysia Police
The Royal Malaysia Police (often abbreviated RMP) ( ms, Polis Diraja Malaysia (PDRM)), is a (primarily) uniformed national and federal police force in Malaysia. The force is a centralised organisation. Its headquarters are located at Bukit Aman ...
,
Malaysian Maritime Enforcement Agency and
RELA Corps
The People's Volunteer Corps ( ms, Jabatan Sukarelawan Malaysia), abbreviated RELA, officially the Malaysia Volunteers Corps Department, is a paramilitary civil volunteer corps formed by the Malaysian government. Their roles include: Helping t ...
.
*
* :
M16A2 is used by the
Mexican Marines in the
Mexican Drug War.
* : ''
Compagnie des Carabiniers du Prince''
*
*
M16A1/M16A2/M16A3/M16A4
* : M16S1s made by Chartered Industries of Singapore provided secretly in violation of license agreements with Colt.
* M16A2 and M16A4; captured M16A2 were also used by Maoist rebels of the
People's Liberation Army, Nepal
The People's Liberation Army, Nepal ( ne, जनमुक्ति सेना, नेपाल) was the armed wing of the Communist Party of Nepal (Maoist) (CPN(M)). The PLA was founded in 2002, in the midst of the Nepal Civil War initiated by ...
during the Nepalese Civil War.
* : C7 and C8 variants are used by the
Military of the Netherlands
The Netherlands Armed Forces ( nl, Nederlandse krijgsmacht) are the military services of the Kingdom of the Netherlands. The core of the armed forces consists of the four service branches: the Royal Netherlands Navy (), the Royal Netherlands Ar ...
and
LSW is used by
Netherlands Marine Corps
The Netherlands Marine Corps ( nl, Korps Mariniers) is the elite naval infantry corps of the Royal Netherlands Navy. The marines trace their origins back to the establishment of the on 10 December 1665, by the then grand pensionary of the Dut ...
.
*: Used by the
National Police of Nicaragua
The National Nicaraguan Police Force ( es, La Policía Nacional Nicaragüense) is the national police of Nicaragua. The force is in charge of regular police functions and, at times, works in conjunction with the Nicaraguan military, making it an ...
and army.
*
* : M16A1 (probably unlicensed copies) used by KPA special forces. Used during the
Gangneung incident in 1996.
*
*
M16A1
* : Used by
Palestinian Security Forces and various local militant forces.
*
M16A1.
*
M16A2.
** : Used by
Bougainville Revolutionary Army
The Bougainville Revolutionary Army (BRA) was a secessionist group formed in 1988 by Bougainvilleans seeking independence from Papua New Guinea (PNG). The leader of the BRA was Francis Ona who led the BRA against the Papua New Guinea Defence Force ...
. Captured from
Papua New Guinea Defence Force.
*
M16A2. M16A1 Used by Navy Special Operation Forces, and by Directorate of Special Operations of the national police
* : Manufactured under license by Elisco Tool and Manufacturing.
M16A1s and M653Ps in use. Supplemented in Special Forces by the M4 carbine.
* : A small number of M16A2s are used by the
Special Actions Detachment
The Special Actions Detachment ( pt, Destacamento de Ações Especiais) or DAE is the special operations maritime unit of the Portuguese Navy. It is part of the Portuguese Marine Corps. Raised in 1985, the DAE is one of the smallest special f ...
of the
Portuguese Navy.
*
M16A1.
*
* : M16A1 and M16A2
*
*: 1,000+ M16A1s in use
* : Local variant of the M16A1 (M16S1) manufactured under license by ST Kinetics.
*
* : Used by
Special Forces
Special forces and special operations forces (SOF) are military units trained to conduct special operations. NATO has defined special operations as "military activities conducted by specially designated, organized, selected, trained and equip ...
.
Likely received from Moroccan stocks.
*: During the
Vietnam War
The Vietnam War (also known by #Names, other names) was a conflict in Vietnam, Laos, and Cambodia from 1 November 1955 to the fall of Saigon on 30 April 1975. It was the second of the Indochina Wars and was officially fought between North Vie ...
, the U.S. provided 27,000 M16 rifles to the
Republic of Korea Armed Forces
The Republic of Korea Armed Forces (), also known as the ROK Armed Forces, are the armed forces of South Korea. The ROK Armed Forces is one of the largest and most powerful standing armed forces in the world with a reported personnel strength of ...
in
Vietnam
Vietnam or Viet Nam ( vi, Việt Nam, ), officially the Socialist Republic of Vietnam,., group="n" is a country in Southeast Asia, at the eastern edge of mainland Southeast Asia, with an area of and population of 96 million, making i ...
. Also, 600,000 M16A1s (Colt Model 603K) were manufactured under license by
Daewoo Precision Industries with deliveries from 1974 to 1985.
KATUSA (Korean Augmentation to the U.S. Army) soldiers who serve in the U.S. Army use the M16A2.
*
*
*
* A small number of M16A2s are used by the
Swedish Armed Forces for familiarization training, as well as a similar number of AKMs, but they are not issued to combat units. The
Ak 4
The Ak 4 (Swedish: ''Automatkarbin 4'') is a Swedish-made version of the Heckler & Koch G3A3 battle rifle. It has been produced in several versions, with minor changes and upgrades.
The original Ak 4 model (Ak 4A) featured a buttstock that is ...
and
Ak 5 rifles are used by
Swedish Army
The Swedish Army ( sv, svenska armén) is the land force of the Swedish Armed Forces.
History
Svea Life Guards dates back to the year 1521, when the men of Dalarna chose 16 young able men as body guards for the insurgent nobleman Gustav Vas ...
.
* M16A1, as well as indigenous Type 65/65K1/65K2, Type 86 and Type 91 (with AR-18 style gas piston system).
*
M16A1/A2/A4. A variant of XM177 replica called Type 49 carbine (ปลส.49) Used in
South Thailand insurgency
The South Thailand insurgency ( th, ความไม่สงบในชายแดนภาคใต้ของประเทศไทย; ms, Pemberontakan di Thailand Selatan) is an ongoing conflict centered in southern Thailand. It ...
.
*
M16A2/A4.
*
M16A1/A2/A4.
*
*
*
* : One of first military customers as UK purchased first AR-15s to be used in jungle warfare in
Indonesia-Malaysia confrontation. The
Colt Canada C8
The Colt Canada C7 is a Canadian family of military rifles, manufactured by Colt Canada (formerly Diemaco prior to 2005), having similar design and function to the Colt M16A3.
The C7 and its variants have been adopted as the standard issue rif ...
(L119A1/L119A2) variant is used by
Royal Military Police Close Protection Units, the
Pathfinder Group
The Pathfinder Platoon is a pathfinder unit of the British Army, and an integral part of 16 Air Assault Brigade. The Pathfinder Platoon acts as the brigade's advance force and reconnaissance force. Its role includes locating and marking drop zone ...
,
United Kingdom Special Forces
The United Kingdom Special Forces (UKSF) is a directorate comprising the Special Air Service, the Special Boat Service, the Special Reconnaissance Regiment, the Special Forces Support Group, 18 (UKSF) Signal Regiment and the Joint Special Force ...
and
43 Commando Fleet Protection Group Royal Marines
The 43 Commando Fleet Protection Group Royal Marines (43 Cdo FP Gp RM), formerly Comacchio Company Royal Marines (1980–1983), Comacchio Group Royal Marines (1983–2001) and Fleet Protection Group Royal Marines (2001–2012), is a 550-man un ...
.
*
*
* : Obtained from
South Vietnam
South Vietnam, officially the Republic of Vietnam ( vi, Việt Nam Cộng hòa), was a state in Southeast Asia that existed from 1955 to 1975, the period when the southern portion of Vietnam was a member of the Western Bloc during part of th ...
following
Vietnam War
The Vietnam War (also known by #Names, other names) was a conflict in Vietnam, Laos, and Cambodia from 1 November 1955 to the fall of Saigon on 30 April 1975. It was the second of the Indochina Wars and was officially fought between North Vie ...
Over 946,000 M16s were captured in 1975 alone.
*
Non-state users
*
East Indonesia Mujahideen
The East Indonesia Mujahideen ( id, Mujahidin Indonesia Timur; Abbreviation, abbreviated MIT) is a terrorist group operating out of Poso, Sulawesi in Indonesia. The group was led by Abu Wardah (also known as Santoso) until he was killed by Indon ...
*
Free Papua Movement
*
**
Bangsamoro Islamic Freedom Fighters
**
Maute Group
The Maute group ( or ), also known as the Islamic State of Lanao, was a radical Islamist group composed of former Moro Islamic Liberation Front guerrillas and foreign fighters led by Omar Maute, the alleged founder of a ''Dawlah Islamiya'', o ...
*
Kurdistan Workers' Party
The Kurdistan Workers' Party or PKK is a Kurdish militant political organization and armed guerrilla movement, which historically operated throughout Kurdistan, but is now primarily based in the mountainous Kurdish-majority regions of south ...
*
New People's Army: Captured from AFP and PNP, supplied by sympathizers, or purchased from the black market.
*
Viet Cong: Captured from U.S. and ARVN forces.
Former users
*
Islamic Republic of Afghanistan
The Islamic Republic of Afghanistan was a presidential republic that ruled Afghanistan from 2004 to 2021. The state was established to replace the Afghan interim (2001–2002) and transitional (2002–2004) administrations, which were formed ...
: Standard issue rifle of the
Afghan National Army
Afghan may refer to:
*Something of or related to Afghanistan, a country in Southern-Central Asia
* Afghans, people or citizens of Afghanistan, typically of any ethnicity
**Afghan (ethnonym), the historic term applied strictly to people of the Pas ...
.
Colt Canada C7 variants also saw limited service.
* M16A1 introduced during the Vietnam War and replaced by the
F88 Austeyr
The Steyr AUG () is an Austrian bullpup assault rifle chambered for the 5.56×45mm NATO intermediate cartridge, designed in the 1960s by Steyr-Daimler-Puch, and now manufactured by Steyr Arms GmbH & Co KG.
It was adopted by the Austrian Army ...
in 1989.
*
Bangsamoro Republik
The Bangsamoro Republik, officially the United Federated States of Bangsamoro Republik (UFSBR), was a short-lived, self-proclaimed, unrecognized List of active separatist movements in Asia, breakaway state in the Philippines. Nur Misuari, chairman ...
*
FARC
*
Free Aceh Movement
The Free Aceh Movement ( id, Gerakan Aceh Merdeka, GAM; ace, Geurakan Acèh Meurdèka / Gěrakan Aceh Měrdeka) was a separatist group seeking independence for the Aceh region of Sumatra, Indonesia. GAM fought against Indonesian government f ...
* : M16A2 variant. Used by the
Royal Hong Kong Regiment.
* : Received from the US government during the
Vietnam War
The Vietnam War (also known by #Names, other names) was a conflict in Vietnam, Laos, and Cambodia from 1 November 1955 to the fall of Saigon on 30 April 1975. It was the second of the Indochina Wars and was officially fought between North Vie ...
and
Laotian Civil War
The Laotian Civil War (1959–1975) was a civil war in Laos which was waged between the Communist Pathet Lao and the Royal Lao Government from 23 May 1959 to 2 December 1975. It is associated with the Cambodian Civil War and the Vietnam War ...
.
*
Moro Islamic Liberation Front
*
M16; replaced in 1988 by
Steyr AUG
The Steyr AUG () is an Austrian bullpup assault rifle chambered for the 5.56×45mm NATO intermediate cartridge, designed in the 1960s by Steyr-Daimler-Puch, and now manufactured by Steyr Arms GmbH & Co KG.
It was adopted by the Austrian Arm ...
, which was being replaced with a
non-Colt M16 variant in 2016.
*
Provisional IRA
The Irish Republican Army (IRA; ), also known as the Provisional Irish Republican Army, and informally as the Provos, was an Irish republicanism, Irish republican paramilitary organisation that sought to end British rule in Northern Ireland, fa ...
– received a number of M16s during
The Troubles
The Troubles ( ga, Na Trioblóidí) were an ethno-nationalist conflict in Northern Ireland that lasted about 30 years from the late 1960s to 1998. Also known internationally as the Northern Ireland conflict, it is sometimes described as an "i ...
in Northern Ireland.
* : M16A1
* : 6,000 M16 and 938,000 M16A1, 1966–1975
*
Conflicts
1960s
*
Vietnam War (1955–1975)
*
Laotian Civil War (1959–1975)
*
Indonesia–Malaysia confrontation (1963–1966)
*
Dominican Civil War (1965)
*
The Troubles (Late 1960s–1998)
*
Colombian conflict (1964–present)
The Colombian conflict ( es, link=no, Conflicto armado interno de Colombia) began on May 27, 1964, and is a low-intensity asymmetric war between the government of Colombia, far-right paramilitary groups, crime syndicates, and far-left gue ...
*
Rhodesian Bush War (1964–1979)
*
Communist insurgency in Thailand (1965–1983)
*
Cambodian Civil War (1968–1975)
*
Communist insurgency in Malaysia (1968–1989)
*
Moro conflict (1969–2019)
*
Communist rebellion in the Philippines (1969–present)
1970s
*
Yom Kippur War
The Yom Kippur War, also known as the Ramadan War, the October War, the 1973 Arab–Israeli War, or the Fourth Arab–Israeli War, was an armed conflict fought from October 6 to 25, 1973 between Israel and a coalition of Arab states led by Egy ...
(1973)
*
Operation Marajoara (1973-1974)
*
Lebanese Civil War (1975–1990)
*
East Timor conflict (1975-1999)
*
Insurgency in Aceh (1976–2005)
*
Shaba II (1978)
*
Cambodian–Vietnamese War (1978–1989)
*
Salvadoran Civil War (1979–1992)
*
Sino-Vietnamese War
1980s
*
Sino-Vietnamese conflicts (1979–1991)
The Sino-Vietnamese conflicts of 1979–1991 were a series of border and naval clashes between the China, People's Republic of China and the Vietnam, Socialist Republic of Vietnam following the Sino-Vietnamese War in 1979. These clashes lasted f ...
*
Soviet–Afghan War
The Soviet–Afghan War was a protracted armed conflict fought in the Democratic Republic of Afghanistan from 1979 to 1989. It saw extensive fighting between the Soviet Union and the Afghan mujahideen (alongside smaller groups of anti-Soviet ...
*
Falklands War
The Falklands War ( es, link=no, Guerra de las Malvinas) was a ten-week undeclared war between Argentina and the United Kingdom in 1982 over two British dependent territories in the South Atlantic: the Falkland Islands and its territorial de ...
(1982)
*
Sri Lankan Civil War (1983–2009)
*
United States invasion of Grenada (1983)
*
Armed resistance in Chile (1973–1990)
Following the 1973 Chilean coup d'état, an armed leftist resistance movement against Augusto Pinochet's dictatorship developed until 1990 when democracy was restored. This conflict was part of the South American theater in the Cold War, with t ...
*
Bougainville Civil War (1988–1998)
*
First Liberian Civil War
The First Liberian Civil War lasted from 1989 to 1997.
President Samuel Doe had established a regime in 1980 but totalitarianism and corruption led to unpopularity and the withdrawal of support from the United States by the late 1980s. The Nat ...
(1989–1997)
*
United States invasion of Panama
The United States invasion of Panama, codenamed Operation Just Cause, lasted over a month between mid-December 1989 and late January 1990. It occurred during the administration of President George H. W. Bush and ten years after the Torrijos– ...
(1989-1990)
1990s
*
Gulf War
The Gulf War was a 1990–1991 armed campaign waged by a 35-country military coalition in response to the Iraqi invasion of Kuwait. Spearheaded by the United States, the coalition's efforts against Iraq were carried out in two key phases: ...
(1990–1991)
*
Somali Civil War
The Somali Civil War ( so, Dagaalkii Sokeeye ee Soomaaliya; ar, الحرب الأهلية الصومالية ) is an ongoing civil war that is taking place in Somalia. It grew out of resistance to the Military dictatorship, military junta wh ...
(1991–present)
*
Sierra Leone Civil War (1991–2002)
*
Burundian Civil War (1993–2005)
*
Cenepa War
The Cenepa War (26 January – 28 February 1995), also known as the Alto Cenepa War, was a brief and localized military conflict between Ecuador and Peru, fought over control of an area in Peruvian territory (i.e. in the eastern side of the Cord ...
(1995)
*
Nepalese Civil War (1996–2006)
*
First Congo War
The First Congo War, group=lower-alpha (1996–1997), also nicknamed Africa's First World War, was a civil war and international military conflict which took place mostly in Zaire (present-day Democratic Republic of the Congo), with major spillo ...
(1996–1997)
*
Second Liberian Civil War
The Second Liberian Civil War was a conflict in the West African nation of Liberia lasted from 1999 to 2003. It was preceded by the First Liberian Civil War, which ended in 1996.
President Charles Taylor came to power in 1997 after victory in t ...
(1999–2003)
2000s
*
War in Afghanistan (2001–2021)
The War in Afghanistan was an armed conflict that began when an Participants in Operation Enduring Freedom, international military coalition led by the United States launched United States invasion of Afghanistan, an invasion of Afghanistan, ...
*
War in Darfur
The War in Darfur, also nicknamed the Land Cruiser War, is a major armed conflict in the Darfur region of Sudan that began in February 2003 when the Sudan Liberation Movement (SLM) and the Justice and Equality Movement (JEM) rebel groups beg ...
(2003–present)
*
Iraq War
{{Infobox military conflict
, conflict = Iraq War {{Nobold, {{lang, ar, حرب العراق (Arabic) {{Nobold, {{lang, ku, شەڕی عێراق (Kurdish languages, Kurdish)
, partof = the Iraq conflict (2003–present), I ...
(2003–2011)
*
South Thailand insurgency
The South Thailand insurgency ( th, ความไม่สงบในชายแดนภาคใต้ของประเทศไทย; ms, Pemberontakan di Thailand Selatan) is an ongoing conflict centered in southern Thailand. It ...
(2004–present)
*
Kivu conflict (2004–present)
*
Insurgency in Paraguay
The insurgency in Paraguay, also known as the Paraguayan People's Army insurgency and the EPP rebellion (from the group's name in Spanish language, Spanish: Ejército del Pueblo Paraguayo), is an ongoing Low intensity conflict, low-level armed co ...
(2005–present)
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2006 Lebanon War
The 2006 Lebanon War, also called the 2006 Israel–Hezbollah War and known in Lebanon as the July War ( ar, حرب تموز, ''Ḥarb Tammūz'') and in Israel as the Second Lebanon War ( he, מלחמת לבנון השנייה, ''Milhemet Leva ...
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Mexican drug war (2006–present)
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2007 Lebanon conflict
The 2007 Lebanon conflict began when fighting broke out between Fatah al-Islam, an Islamist militant organization, and the Lebanese Armed Forces (LAF) on May 20, 2007 in Nahr al-Bared, an UNRWA Palestinian refugee camp near Tripoli.
It was t ...
(2007)
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Cambodian–Thai border dispute (2008–2011)
2010s
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Militias-Comando Vermelho conflict (2010–present)
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Syrian civil war (2011–present)
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Infighting in the Gulf Cartel (2011–present)
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2013 Lahad Datu standoff
The 2013 Lahad Datu standoff, also known as the Lahad Datu incursion or Operation Daulat ( ms, Operasi Daulat), was a military conflict in Lahad Datu District, Sabah, Malaysia, that started on 11 February 2013, lasting until 24 March 2013. The ...
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Iraqi Civil War (2014–2017)
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Operation Madago Raya
Operation Madago Raya ( id, Operasi Madago Raya), previously known as Operation Tinombala, is a joint police–military operation conducted by the Indonesian National Police and the Indonesian Armed Forces to capture and/or eliminate members of Mu ...
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Battle of Marawi (2017)
2020s
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Republican insurgency in Afghanistan (2021-present)
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2021 Beirut clashes
The 2021 Beirut clashes, also known as the 2021 Beirut massacre, Tayouneh Incident or Mini 2008 Lebanon conflict, May 7, were a series of clashes that erupted in the Tayouneh neighborhood of the Lebanon, Lebanese capital of Beirut on 14 October ...
(2021)
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2022 Russian invasion of Ukraine
On 24 February 2022, in a major escalation of the Russo-Ukrainian War, which began in 2014. The invasion has resulted in tens of thousands of deaths on both sides. It has caused Europe's largest refugee crisis since World War II. An ...
See also
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Adaptive Combat Rifle
The Adaptive Combat Rifle (ACR) is a modular assault rifle designed by Magpul Industries of Austin, Texas, and known initially as the Masada.
In late January 2008, Bushmaster Firearms International entered into a licensing agreement with Magpul ...
*
List of Colt AR-15 and M16 rifle variants
This article describes the many variations of the Colt AR-15 and M16 rifle family of weapons produced by Colt's Manufacturing Company. Weapons patterned on the original ArmaLite AR-15 design have been produced by numerous manufacturers and h ...
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Colt 9 mm SMG
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Comparison of the AK-47 and M16
The two most common rifles in the world are the Soviet Union, Soviet AK-47 and the United States, American M16 rifle, M16. These Cold War-era rifles have been used in conflicts both large and small since the 1960s. They are used by military, po ...
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Daewoo K2
Daewoo Precision Industries K2 assault rifle is the standard service rifle of the South Korean military. It was developed by the South Korean Agency for Defense Development and manufactured by S&T Motiv (formerly Daewoo Precision Industries) and ...
,
Republic of Korea Armed Forces
The Republic of Korea Armed Forces (), also known as the ROK Armed Forces, are the armed forces of South Korea. The ROK Armed Forces is one of the largest and most powerful standing armed forces in the world with a reported personnel strength of ...
(South Korea) assault rifle
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Heckler & Koch HK416
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List of individual weapons of the U.S. armed forces
This is a list of weapons served individually by the United States armed forces. While the general understanding is that crew-served weapons require more than one person to operate them, there are important exceptions in the case of both squad a ...
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M203 40 mm grenade launcher
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Norinco CQ
The Type CQ is an unlicensed Chinese variant of the M16 rifle manufactured by Norinco. According to the Norinco website, the rifle is officially known as CQ 5.56.
It can be distinguished from other AR-15 and M-16 pattern rifles by its long, r ...
, M16 clone developed by China
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Robinson Arms XCR
The Robinson Armament Co. XCR is a multi-caliber, gas piston weapon system developed by Robinson Armament Co. for U.S. Special Operations Command (SOCOM) to satisfy the requirements of the SOF Combat Assault Rifle, or SCAR competition, but w ...
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Rubber duck (military)
In the United States military, a rubber duck, or "rubber ducky", or "Blue Gun", or "Red Gun" is a non-functional training weapon that is fully or partially made of rubber or plastic. They are usually M16 rifles, and are commonly used in basic tr ...
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T65 assault rifle, AR-15 variant developed by
ROC Army
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Winchester LMR
The Winchester LMR is a prototype rifle that was developed for military use but was sidelined in 1964 by the AR-15
References
{{reflist
Assault rifles of the United States
Trial and research firearms of the United States ...
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Squad Designated Marksman Rifle
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SEAL Recon Rifle
The SEAL Recon Rifle (also known as the "Sniper M4" and "Recce") is a heavily modified M16-series rifle intended to provide US Navy SEAL snipers with a versatile, accurate, lightweight, and relatively compact weapon chambered in 5.56×45mm NAT ...
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Marine Scout Sniper Rifle
The Marine Scout Sniper Rifle or MSSR is a semi-automatic designated marksman rifle developed from the Colt M16A1 rifle by the Philippine Marine Corps Scout Snipers due to the lack of a dedicated precision rifle which is used in the Armed Forces ...
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Table of handgun and rifle cartridges
This is a table of selected pistol/submachine gun and rifle/machine gun cartridges by common name. Data values are the highest found for the cartridge, and might not occur in the same load (e.g. the highest muzzle energy might not be in the same ...
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List of assault rifles
An assault rifle is a rifle that uses an intermediate cartridge, a detachable magazine, and can switch between semi-automatic/fully automatic fire. Assault rifles are currently the standard service rifles in most modern armies. Some rifles listed ...
References
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Further reading
* Modern Warfare, Published by Mark Dartford, Marshall Cavendish (London) 1985
* Afonso, Aniceto and Gomes, Carlos de Matos, ''Guerra Colonial'' (2000),
* Bartocci, Christopher R. ''Black Rifle II The M16 into the 21st Century''. Cobourg, Ontario, Canada: Collector Grade Publications Incorporated, 2004.
*
*
* Hutton, Robert, ''The .223'', Guns & Ammo Annual Edition, 1971.
* McNaugher, Thomas L.
Marksmanship, Mcnamara and the M16 Rifle: Organisations, Analysis and Weapons Acquisition
*
* Pikula, Sam (Major), ''The ArmaLite AR-10'', 1998
* Rose, Alexander. ''American Rifle-A Biography.'' 2008; Bantam Dell Publishing. .
* Urdang, Laurence, Editor in Chief. ''The Random House Dictionary of the English Language.'' 1969; Random House/New York.
* U.S. Army; Sadowski, Robert A., Editor. ''The M16A1 Rifle: Operation and Preventive Maintenance'' Enhanced, hardcover edition 2013; Skyhorse, New York, NY.
External links
Colt's Manufacturing: The M16A4 RiflePEO Soldier M16 fact sheetCombat Training with the M16 Manual*
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* , artwork by
Will Eisner
William Erwin Eisner (March 6, 1917 – January 3, 2005) was an American cartoonist, writer, and entrepreneur. He was one of the earliest cartoonists to work in the American comic book industry, and his series ''The Spirit'' (1940–1952) was no ...
.
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{{Authority control
ArmaLite AR-10 derivatives
5.56×45mm NATO assault rifles
Modular firearms
Cold War firearms of the United States
Rifles of the Cold War
Colt rifles
Assault rifles of the United States
United States Marine Corps equipment
Weapons and ammunition introduced in 1964
AR-15 style rifles
Gas-operated firearms