Selective fire is the capability of a

weapon A weapon, arm or armament is any implement or device that can be used to deter, threaten, inflict physical damage, harm, or kill. Weapons are used to increase the efficacy and efficiency of activities such as hunting, crime, law enforcement, s ...

to be adjusted to fire in semi-automatic,

fully automatic An automatic firearm is an auto-loading firearm that continuously chambers and fires rounds when the trigger mechanism is actuated. The action of an automatic firearm is capable of harvesting the excess energy released from a previous discharge ...

, and/or burst mode. The modes are chosen by means of a selector switch, which varies depending on the weapon's design. Some selective-fire weapons have burst fire mechanisms to limit the maximum number of shots fired automatically in this mode. The most common limits are two or three rounds per trigger pull. Fully automatic fire refers to the ability for a weapon to fire continuously until either the feeding mechanism is emptied or the trigger is released. Semi-automatic refers to the ability to fire one round per trigger pull. The presence of selective fire modes on

firearm A firearm is any type of gun designed to be readily carried and used by an individual. The term is legally defined further in different countries (see Legal definitions). The first firearms originated in 10th-century China, when bamboo tubes ...

s permits more efficient use of rounds to be fired for specific needs, versus having a single mode of operation, such as fully automatic, thereby conserving ammunition while maximizing on-target accuracy and effectiveness. This capability is most commonly found on military weapons of the 20th and 21st centuries.

History

Early attempts at this technology were hindered by one or both of two obstacles: over-powerful ammunition and mechanical complexity. The latter led to excessive weight and unreliability in the firearm. One of the earliest designs dates to just before the end of the 19th century with the development of the

Cei-Rigotti The Cei-Rigotti (also known as the Cei gas rifle) is an early automatic rifle created in the final years of the 19th century by Amerigo Cei-Rigotti, an officer in the Royal Italian Army. Although the rifle was never officially adopted by any mili ...

, an early

automatic rifle An automatic rifle is a type of autoloading rifle that is capable of fully automatic fire. Automatic rifles are generally select-fire weapons capable of firing in semi-automatic and automatic firing modes (some automatic rifles are capable of ...

created by Italian Army officer Amerigo Cei-Rigotti that had selective-fire capability (single shots or burst). Another is the

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 . ...

(BAR) developed during the

First World War World War I (28 July 1914 11 November 1918), often abbreviated as WWI, was one of the deadliest global conflicts in history. Belligerents included much of Europe, the Russian Empire, the United States, and the Ottoman Empire, with fightin ...

. The BAR and its subsequent designs incorporated a variety of selective-fire functions. The first design (M1918) is a selective-fire, air-cooled automatic rifle that used a trigger mechanism with a fire selector lever that enabled operating in either semi-automatic or fully automatic firing modes. The selector lever is located on the left side of the receiver and is simultaneously the manual safety (selector lever in the "S" position – weapon is "safe", "F" – "Fire", "A" – "Automatic" fire).Ballou, James L., ''Rock in a Hard Place: The Browning Automatic Rifle'', Ontario, California: Collector Grade Publications Inc., (2000) The next version (M1918A1) had a unique rate-of-fire reducer mechanism purchased from FN Herstal with two rates of automatic fire. This reducer mechanism was later changed to one designed by the

Springfield Armory The Springfield Armory, more formally known as the United States Armory and Arsenal at Springfield located in the city of Springfield, Massachusetts, was the primary center for the manufacture of United States military firearms from 1777 until ...

. The final version (M1918A2) provided two selectable rates of fully automatic fire only. During

World War II World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposin ...

the Germans began development of the selective-fire function which resulted in the FG 42

battle rifle A battle rifle is a service rifle chambered to fire a fully powered cartridge. The term "battle rifle" is a retronym created largely out of a need to better differentiate the intermediate cartridge, intermediate-powered assault rifles (e.g. the S ...

developed in 1942 at the request of the German Air Force (''

Luftwaffe The ''Luftwaffe'' () was the aerial-warfare branch of the German ''Wehrmacht'' before and during World War II. Germany's military air arms during World War I, the ''Luftstreitkräfte'' of the Imperial Army and the '' Marine-Fliegerabtei ...

'') in 1941. Another German design that used selective fire was the StG 44 that was the first of its kind to see major deployment and is considered by many historians to be the first modern assault rifle. "The principle of this weapon -- the reduction of muzzle impulse to get useful automatic fire within actual ranges of combat -- was probably the most important advance in small arms since the invention of smokeless powder."http://pogoarchives.org/labyrinth/09/02.pdf M16 Rifle Case Study. Prepared for the President's Blue Ribbon Defense Panel. March 16, 1970. By Richard R. Hallock, Colonel U.S. Army (Retired) The selective-fire function was later seen in the Russian

AK-47 The AK-47, officially known as the ''Avtomat Kalashnikova'' (; also known as the Kalashnikov or just AK), is a gas operated, gas-operated assault rifle that is chambered for the 7.62×39mm cartridge. Developed in the Soviet Union by Russian s ...

(designed in 1946), the Belgian FN FAL (designed 1947-53) the British EM-2 (designed in 1948), and the U.S.

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 com ...

(designed in 1957) and its AR derivatives.

Design

Selective-fire weapons, by definition, have a semi-automatic mode, where the weapon automatically reloads the

chamber Chamber or the chamber may refer to: In government and organizations * Chamber of commerce, an organization of business owners to promote commercial interests *Legislative chamber, in politics * Debate chamber, the space or room that houses delib ...

after each fired round, but requires the trigger be released and pulled again before firing the next round. This allows for rapid and (in theory) aimed fire. In some weapons, the selection is between different rates of automatic fire and/or varying burst limiters. The selection is often by a small rotating switch often integrated with the safety catch or a switch separate from the safety, as in the British

SA80 The SA80 (Small Arms for the 1980s) is a British family of 5.56×45mm NATO service weapons used by the British Army. The L85 Rifle variant has been the standard issue service rifle of the British Armed Forces since 1987, replacing the L1A1 Se ...

family. Another method is a weighted trigger, such as the Steyr AUG, which will fire a single shot when 4.0 - 7.1 kg (8.8 – 15.4 lbs.) of weight is exerted on the trigger, and then become fully automatic when over 7.1 kg (15.4 lbs.) of weight is applied. This is useful for emergency situations where a rapid volley of rounds is more effective for suppressing a close enemy rather than a single-round burst. Some selective-fire weapons offer a burst mode as the second option, where each pull of the trigger automatically fires a predetermined number of rounds (generally two or three), but will not fire any more until the trigger is released and pulled again. The current U.S. standard assault rifle, the

M16A4 The M16 rifle (officially designated Rifle, Caliber 5.56 mm, M16) is a family of military rifles adapted from the ArmaLite AR-15 rifle for the United States military. The original M16 rifle was a 5.56×45mm automatic rifle with a 20-roun ...

, and 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 ...

variant of this rifle fire a maximum of three rounds with each pull of the trigger in burst mode. In this design, it retains the count of previously fired rounds and may fire fewer than three rounds. Other designs reset the count with each trigger pull, allowing a uniform three-round burst as long as rounds remain. A common version of the

Heckler & Koch MP5 The Heckler & Koch MP5 (german: Maschinenpistole 5) is a 9x19mm Parabellum submachine gun, developed in the 1960s by a team of engineers from the German small arms manufacturer Heckler & Koch. There are over 100 variants and clones of the MP5, ...

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 ...

(which is widely used by

SWAT In the United States, a SWAT team (special weapons and tactics, originally special weapons assault team) is a police tactical unit that uses specialized or military equipment and tactics. Although they were first created in the 1960s to ...

teams and

military A military, also known collectively as armed forces, is a heavily armed, highly organized force primarily intended for warfare. It is typically authorized and maintained by a sovereign state, with its members identifiable by their distinct ...

special operations personnel) fires single shots, three-round-bursts, and automatically. A special variant uses a two-round-burst to minimize the chances of missing with a third round. Some automatic cannons have larger burst limiters to coincide with higher rates of fire.

References

{{DEFAULTSORT:Selective Fire Firearm actions

History

Design

See also

References