The SR-25 (Stoner Rifle-25) is a

designated marksman rifle A designated marksman rifle (DMR) is a modern telescopic sight, scoped high-Accuracy and precision, precision rifle used by infantry in the designated marksman (DM) role. It generally fills the engagement effective range, range gap between a serv ...

and semi-automatic

sniper rifle A sniper rifle is a high-precision, long range shooting, long-range rifle. Requirements include high accuracy, reliability, mobility, concealment, and optics, for anti-personnel weapon, anti-personnel, anti-materiel rifle, anti-materiel and sur ...

Eugene Stoner Eugene Morrison Stoner (November 22, 1922 – April 24, 1997) was an American machinist and firearms designer who is most associated with the development of the ArmaLite AR-15 rifle that was redesigned and modified by Colt's Manufacturing Compan ...

and manufactured by

Knight's Armament Company Knight's Armament Company (KAC) is an American firearms and firearms parts manufacturer, known for producing the Rail Interface System (RIS) and the Rail Adapter System (RAS) grips for firearms use. The company produces a variety of firearms, ...

. The SR-25 uses a

rotating bolt Rotating bolt is a method of locking the breech (or rear barrel) of a firearm closed for firing. Johann Nicolaus von Dreyse developed the first rotating bolt firearm, the "Dreyse needle gun", in 1836. The Dreyse locked using the bolt handle ra ...

and a Stoner bolt and carrier piston gas system. It is loosely based on Stoner'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 manufacturer), Fairchild Aircraft Corporation). When first introduced in 1956 ...

, rebuilt in its original

7.62×51mm NATO The 7.62×51mm NATO (official NATO nomenclature 7.62 NATO) is a rimless, straight walled, bottlenecked, centerfire rifle cartridge. It is a standard for small arms among NATO countries. First developed in the 1950s, the cartridge had first be ...

caliber. Up to 60% of parts of the SR-25 are interchangeable with the AR-15 and M16—everything but the upper and lower receivers, the

hammer A hammer is a tool, most often a hand tool, consisting of a weighted "head" fixed to a long handle that is swung to deliver an impact to a small area of an object. This can be, for example, to drive nail (fastener), nails into wood, to sh ...

, the

barrel A barrel or cask is a hollow cylindrical container with a bulging center, longer than it is wide. They are traditionally made of wooden stave (wood), staves and bound by wooden or metal hoops. The word vat is often used for large containers ...

assembly and the bolt carrier group. SR-25 barrels were originally manufactured by

Remington Arms Remington Arms Company, LLC, was an American firearms manufacturer, manufacturer of firearms and ammunition. It was formerly owned by the Remington Outdoor Company, which went bankrupt in 2020 with its lines of business sold to several purchase ...

with its 5R (five grooves, right twist)

rifling Rifling is the term for helical grooves machined into the internal surface of a firearms's barrel for imparting a spin to a projectile to improve its aerodynamic stability and accuracy. It is also the term (as a verb) for creating such groov ...

, with twist 1:11.25. The heavy barrel is free-floating, so handguards are attached to the front of the receiver and do not touch the barrel.

History

In the late 1950s,

designed the

battle rifle to equip U.S. troops. It was accurate for an auto-loading rifle, but it lost the competition to the M14 rifle. The patent rights for the AR-10 and the AR-15 were sold to

Colt's Manufacturing Company Colt's Manufacturing Company, LLC (CMC, formerly Colt's Patent Firearms Manufacturing Company) is an American firearms manufacturer, founded in 1855 by Samuel Colt that has become a subsidiary of Czech holding company Colt CZ Group. It is th ...

. Colt focused on the AR-15, giving others the ability to capitalize on the AR-10 system.Knight’s Armament M110: The New Breed of Sniper Rifle
- SAdefensejournal.com, 5 January 2012 In the early 1990s, Stoner joined

. He continued his AR-10 design work. The result was the SR-25 (adding together the numbers of the AR-10 and AR-15) which improved the AR-10 design with M16A2 advancements and parts commonality. The original SR-25 was released in the early 1990s and had a heavy free-floating match grade barrel with a

fiberglass Fiberglass (American English) or fibreglass (English in the Commonwealth of Nations, Commonwealth English) is a common type of fibre-reinforced plastic, fiber-reinforced plastic using glass fiber. The fibers may be randomly arranged, flattened i ...

handguard. It had a flat top upper receiver with a Mil-Std 1913 rail for mounting optics and a 2-stage match grade trigger. The bolt carrier was similar to the AR-10's, being chrome plated and having a captive firing pin retainer pin. The SR-25 was designed specifically to fire open-tip match cartridges. Accuracy was guaranteed at or under 1

minute of angle A minute of arc, arcminute (abbreviated as arcmin), arc minute, or minute arc, denoted by the symbol , is a unit of angular measurement equal to of a degree. Since one degree is of a turn, or complete rotation, one arcminute is of a tu ...

. At first, AR-10 type 20-round magazines were used, but they were later replaced by steel 20-round magazines resembling those used by the M16.

United States Special Operations Command The United States Special Operations Command (USSOCOM or SOCOM) is the unified combatant command charged with overseeing the various special operations component commands of the Army, Marine Corps, Navy, and Air Force of the United States A ...

took interest in the SR-25, particularly its high magazine capacity and faster engagement time compared to bolt-action rifles. After some modifications, SOCOM adopted the SR-25 as the Mk 11 MOD 0 in May 2000. Changes included a shorter barrel that could fire M118 and M118LR 7.62×51mm NATO rounds and had a quick detachable sound suppressor mount. An free-floating handguard rail system allowed mounting accessories. Flip-up front sights and adjustable back-up iron sights were added, and an M16A2 stock and pistol grip were used. Beginning in mid-2011, SOCOM began divesting the Mk 11 MOD 0 from their inventory and replacing it with the SSR Mk 20, the sniper variant of the FN SCAR. The Mk 11 was completely replaced by 2017.

Design

The SR-25 enhanced match rifle utilizes the newer URX II Picatinny-

Weaver Weaver or Weavers may refer to: Activities * A person who engages in weaving fabric Animals * Various birds of the family Ploceidae * Crevice weaver spider family * Orb-weaver spider family * Weever (or weever-fish) Arts and entertainmen ...

rail system, rather than the older Mk 11 free-floating RAS, on the top of the receiver to accept different scope mounts or a carrying handle with iron sights (front sight mounted on the rail located on the forward end of the non-modular handguard). The match version is designed to shoot at a precision of 0.5 minutes of angle, which corresponds to groups at . The Mk 11 MOD 0 system is chambered for 7.62×51mm NATO, and is designed for match-grade ammunition. The Mk 11 system includes the rifle, 20 round box magazines, QD (Quick Detachable) scope rings, Leupold Mark 4 Mil-dot riflescope, Harris swivel-base bipod on a Knight's mount, and QD

sound suppressor A silencer, also known as a sound suppressor, suppressor, or sound moderator, is a gun barrel#Muzzle, muzzle device that suppresses the muzzle blast, blast created when a gun (firearm or airgun) is discharged, thereby reducing the sound inten ...

, which is also manufactured by Knight's Armament Co. Flip-up BUIS (Back up iron sights) are attached to the modified gas block and upper receiver. The Mk 11 MOD 0 utilizes an Obermeyer match target barrel, along with a RAS (Rail Accessory System) fore-end made by KAC, consisting of an long match fore-end. The RAS allows for quick attachment/detachment of MIL-STD-1913 components. The aluminum fore-end makes no contact with the barrel forward of the receiver, allowing for improved accuracy. The Mk 11 MOD 0 has an empty weight of , and an overall length of . The civilian version, using the longer match barrel, is guaranteed to produce groupings of less than at , or 0.3

angular mil A milliradian ( SI-symbol mrad, sometimes also abbreviated mil) is an SI derived unit for angular measurement which is defined as a thousandth of a radian (0.001 radian). Milliradians are used in adjustment of firearm sights by adjusting t ...

, using factory match loads. During the

Iraq War The Iraq War (), also referred to as the Second Gulf War, was a prolonged conflict in Iraq lasting from 2003 to 2011. It began with 2003 invasion of Iraq, the invasion by a Multi-National Force – Iraq, United States-led coalition, which ...

, the

United States Marine Corps The United States Marine Corps (USMC), also referred to as the United States Marines or simply the Marines, is the maritime land force service branch of the United States Department of Defense. It is responsible for conducting expeditionar ...

ordered 180 Mk 11 MOD 1 rifles which were Mk 11s equipped with the upper receiver of the

M110 Semi-Automatic Sniper System The M110 Semi Automatic Sniper System (M110 SASS) is an American Semi-automatic firearm, semi-automatic sniper rifle that is chambered for the 7.62×51mm NATO round. It is manufactured by Knight's Armament Company, developed from the Knight's A ...

. The M110 upper gave the Mk 11 MOD 1 a URX modular rail system and a flash suppressor on the barrel. These saw limited use before they were phased out when the Marines chose to purchase the Mk 11 MOD 2, which was simply the

USSOCOM The United States Special Operations Command (USSOCOM or SOCOM) is the unified combatant command charged with overseeing the various special operations component commands of the United States Army Special Operations Command, Army, United Stat ...

and U.S. Navy designation for the complete M110 rifle. The SR-25 Enhanced Match (E.M.) Carbine is very similar to the M110 Semi-Automatic Sniper System, though the M110 utilizes the newer URX Rail system, a length-adjustable fixed buttstock, and an integrated flash suppressor. Starting in late 2011, USMC snipers began to replace Mk 11 MOD 0 rifles with the M110 on a one-for-one basis.

Users

Australian Army The Australian Army is the principal Army, land warfare force of Australia. It is a part of the Australian Defence Force (ADF), along with the Royal Australian Navy and the Royal Australian Air Force. The Army is commanded by the Chief of Army ...

Royal Australian Air Force The Royal Australian Air Force (RAAF) is the principal Air force, aerial warfare force of Australia, a part of the Australian Defence Force (ADF) along with the Royal Australian Navy and the Australian Army. Constitutionally the Governor-Gener ...

Airfield Defence Guards Airfield Defence Guards (ADG) are a Muster (military), mustering of the Royal Australian Air Force (RAAF) that are dedicated to the security and ground defence of airbases and other military aviation assets.#refDefJobs, Defence Jobs website Acces ...

and

Police Tactical Group Police tactical group (PTG) is the generic term used to refer to highly trained Australian and New Zealand police tactical units that tactically manage and resolve high-risk incidents, including sieges, armed-offender situations and terrorist incid ...

s. *: Special Warfare Diving and Salvage (SWADS) of

Bangladesh Navy The Bangladesh Navy () is the naval warfare branch of the Bangladesh Armed Forces, responsible for the defence of Bangladesh's of maritime territorial area from any external threat, the security of sea ports and exclusive economic zones of Ban ...

. *: IDF

special forces Special forces or 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 ...

. *:

Philippine National Police The Philippine National Police (PNP; ) is the national police force of the Philippines. Its national headquarters is located at Camp Crame in Bagong Lipunan ng Crame, Quezon City. Currently, it has approximately 228,000 personnel to police a pop ...

Special Action Force,

Philippine Army The Philippine Army (PA) () is the main, oldest and largest branch of the Armed Forces of the Philippines (AFP), responsible for ground warfare. , it had an estimated strength of 143,100 soldiers The service branch was established on December ...

Light Reaction Regiment The Light Reaction Regiment (LRR) is the special operations unit of the Philippine Army (PA), under the operational control of the Special Operations Command (Philippines), Armed Forces of the Philippines Special Operations Command (AFPSOCOM). ...

*: GROM. *:

Republic of Korea Navy Special Warfare Flotilla The Republic of Korea Navy Special Warfare Flotilla (; Hanja: 大韓民國海軍特殊戰戰團), name abbreviated NAVSPECWARFLOT or WARFLOT, is a special forces, special operations force of the Republic of Korea Navy. The WARFLOT is most comm ...

Royal Thai Army The Royal Thai Army or RTA (; ) is the army of Thailand and the oldest and largest branch of the Royal Thai Armed Forces. History Origin The Royal Thai Army is responsible for protecting the kingdom's sovereignty. The army was formed in 187 ...

. *:

Gendarmerie General Command The Gendarmerie General Command () is the national gendarmerie force of the Republic of Turkey. It is a service branch of the Turkish Ministry of Interior responsible for the maintenance of the public order in areas that fall outside the jurisdi ...

United States Military The United States Armed Forces are the Military, military forces of the United States. U.S. United States Code, federal law names six armed forces: the United States Army, Army, United States Marine Corps, Marine Corps, United States Navy, Na ...

Jones, Richard D. ''Jane's Infantry Weapons 2009/2010''. Jane's Information Group; 35th edition (January 27, 2009). .

Gallery

File:SR-25 pic01.jpg,

Israeli Defense Forces Israeli may refer to: * Something of, from, or related to the State of Israel * Israelis, citizens or permanent residents of the State of Israel * Modern Hebrew, a language * ''Israeli'' (newspaper), published from 2006 to 2008 * Guni Israeli (b ...

SR-25 with a suppressor. File:USMC SR-25 SAMR.jpg, A U.S. Marine general fires the Mk 11. File:110217-G-6349A-480 MSRT Precision Marksmen Observer Team.jpg, Marksmen from the U.S. Coast Guard

Maritime Security Response Team Maritime may refer to: Geography * Maritime Alps, a mountain range in the southwestern part of the Alps * Maritime Region, a region in Togo * Maritime Southeast Asia * The Maritimes, the Canadian provinces of Nova Scotia, New Brunswick, and Prin ...

with Mk 11s File:US Navy 100717-N-0683T-292 A U.S. Navy SEAL sniper waves to the crowd during a capabilities demonstration at Joint Expeditionary Base Little Creek, Va.jpg, Navy SEALs sniper with MK 11. File:Magav-Facebook--Yamam-0006 (sniper).jpg, YAMAM sniper equipped with the SR-25 Mk 11.

References

External links