The SR-556 is a semiautomatic

AR-15 style rifle An AR-15-style rifle is any lightweight semi-automatic rifle based on the Colt AR-15 design. The original ArmaLite AR-15 is a scaled-down derivative of Eugene Stoner's ArmaLite AR-10 design. The then Fairchild Engine and Airplane Corporation ...

manufactured by U.S. firearms company Sturm, Ruger & Co. The rifle was introduced in 2009 in

223 Remington The .223 Remington (designated as the 223 Remington by the SAAMI and 223 Rem by the CIP) is a rimless, bottlenecked rifle cartridge. It was developed in 1957 by Remington Arms and Fairchild Industries for the U.S. Continental Army Command ...

/ 5.56×45mm NATO and as a

.308 Winchester The .308 Winchester is a smokeless powder rimless bottlenecked rifle cartridge widely used for hunting, target shooting, police, military, and personal protection applications globally. It is similar but not identical to the 7.62×51mm NATO ...

AR-10 variant in 2013, the SR-762.Gilbert, Glenn M.,
Ruger's SR-556: Ready To Run, Right Out Of The Box
', American Rifleman, October 2009 It is one of several 21st-century AR-15 rifles to use gas piston operation (SR-556). In January 2016 Ruger discontinued all SR-556 rifles and introduced a new takedown variant with a lightweight

KeyMod KeyMod is a universal interface system for firearm accessory components designed to supersede the MIL-STD-1913 accessory rails. The concept was first created by VLTOR Weapon Systems of Tucson, Arizona, and released through Noveske Rifleworks of ...

handguard.

Overview

The rifle features a "two-stage" piston mechanism as opposed to the semi-

direct impingement Direct impingement is a type of gas operation for a firearm that directs gas from a fired cartridge indirectly (through the barrel, through a gas block, and then through a gas tube) into the bolt carrier or slide assembly to cycle the action. F ...

system of the

AR-15 An AR-15-style rifle is any lightweight semi-automatic rifle based on the Colt AR-15 design. The original ArmaLite AR-15 is a scaled-down derivative of Eugene Stoner's ArmaLite AR-10 design. The then Fairchild Engine and Airplane Corporation ...

. Gas flow is controlled by a four position regulator. Several key parts, such as the short stroke gas piston, gas regulator, and bolt/carrier group are chrome plated. The bolt carrier features an integral lug in place of the AR-15's gas key. The flash suppressor is similar to Ruger's

AC-556 The Mini-14 is a lightweight semi-automatic rifle manufactured by Sturm, Ruger & Co. Introduced in 1973, it is based on the M14 rifle and is essentially a scaled-down version chambered in 5.56×45mm NATO. It is made in a number of variants, inc ...

and Mini-14GB. The 5.56 rifle includes a number of other manufacturer's parts such as a Troy Industries railed handguard and Samson folding

iron sight Iron sights are a system of physical alignment markers (usually made of metallic material) used as a sighting device to assist the accurate aiming of ranged weapons (such as a firearm, airgun, crossbow or even compound bow), or less commonly ...

s, a Hogue rubberized pistol grip, and three

Magpul Magpul Industries Corporation is an American designer and manufacturer of high-tech polymer and composite firearms accessories like M-LOK. Magpul Industries takes its name from its first product, the MagPul (Magazine Puller), an accessory for th ...

PMAG 30-round STANAG magazines. The 7.62 variant uses SR-25 pattern magazines. The SR-556SC comes with three 10-round magazines and does not have the flash hider or collapsible stock, making it compliant in several states with restrictive rifle laws. The barrel is , chrome lined, and features a six groove, right hand, 1: twist. In August 2010, Ruger announced that the rifle would be offered in the

6.8mm Remington SPC The 6.8mm Remington Special Purpose Cartridge (6.8 SPC, 6.8 SPC II or 6.8×43mm) is a rimless bottlenecked intermediate rifle cartridge that was developed by Remington Arms in collaboration with members of the U.S. Army Marksmanship Unit and ...

cartridge. Ruger's introduction of the SR-556 was met with some criticism for its high price tag of around US$2,000. Ruger products are usually known for affordability, but the SR-556 is essentially a regular AR-15 albeit with a different, more complicated operating system. It differs from the less expensive alternatives like the Smith & Wesson M&P Sport and Sport II model rifles, of which the original Sport model lacked a

forward assist Forward assisting is the practice of moving the bolt or bolt carrier of a firearm fully forward when the return spring has not done so (or there is a chance that it will not have done so). Some firearms have a dedicated device to allow forward a ...

and dust cover. The SR-556 was also criticized for being heavier than other AR-15s. Ruger addressed these shortcomings by introducing a lighter and less expensive rifle, the SR-556E.

Gallery

File:Srfired.jpg, Firing the Ruger SR-556 File:Srgaskey.jpg, Adjustable gas key on Ruger SR-556 piston rifle File:Gassyt.jpg, Elements of Ruger SR-556 gas system File:Rugersrcarrier.jpg, Top: Bolt and carrier for Ruger SR-556 gas piston rifle
Lower: Bolt and carrier for direct impingement AR 15 Rifle.

References

External links

Ruger official website
{{ArmaLite AR-10 derivatives .300 BLK firearms 5.56×45mm NATO semi-automatic rifles Rifles of the United States Short stroke piston firearms SR-556 ArmaLite AR-10 derivatives Weapons and ammunition introduced in 2009

Overview

Gallery

See also

References

External links