Ruger SR-556
Summary
| Country | 🇺🇸 United States |
| Category | Assault rifle |
| Manufacturer | Sturm, Ruger & Co |
Technical specifications
| Ruger SR-556 | |
|---|---|
| Fire Rate | 700 rounds/min. |
| Caliber | 5.56 x 45 mm OTAN |
| Magazine | 30 rounds |
| Length | 914 mm (36.0 in) |
| Weight | 3.6 kg (7.9 lb) |
| Range | 400 m (1312 ft) |
Description
The Ruger SR-556 is a semi-automatic rifle patterned after the AR-15 platform, manufactured by Sturm, Ruger & Co. Introduced in 2009, it was initially chambered in .223 Remington and 5.56×45mm NATO. A variant chambered in .308 Winchester, known as the SR-762, followed in 2013. The SR-556 is one of several AR-style rifles to utilize a gas piston operating system.
The rifle incorporates a short-stroke piston mechanism, in contrast to the semi-direct impingement system commonly found in AR-15 rifles. Gas flow to the system is regulated by a four-position adjustable control. Key components, such as the gas piston, gas regulator, and the bolt and carrier group, are chrome plated. The bolt carrier is designed with an integral lug, which serves the function typically performed by a gas key. The flash suppressor design resembles those used on Ruger's AC-556 and Mini-14GB models. The 5.56mm version as introduced came equipped with several parts from other manufacturers, including a railed handguard from Troy Industries, Samson folding iron sights, and a Hogue rubberized pistol grip. It was also supplied with three 30-round Magpul PMAGs designed to accept STANAG magazines. The rifle features a 409 mm (16.12 in) barrel which is chrome lined, has six grooves, and a right-hand twist rate of 1:230 mm (9 in).
Several variations of the SR-556 were developed:
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The SR-762, chambered in .308 Winchester, uses SR-25 pattern magazines.
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The SR-556C model was introduced in 2010.
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The SR-556SC, configured to meet certain state-level regulations, featuring three 10-round magazines and lacking a flash hider and collapsible stock.
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The SR-556E, a lighter and less expensive rifle.
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A version in 6.8mm Remington SPC, announced in August 2010.
All original SR-556 rifle models were discontinued in January 2016. Subsequently, a new takedown variant, the Ruger SR-556 Takedown, featuring a lightweight KeyMod handguard, was introduced in 2017.