Ruger SR-556

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Ruger SR-556
Ruger SR-556 - Standard Configuration
Type Semi-automatic rifle
Place of origin  United States
Production history
Designed 2009
Manufacturer Sturm, Ruger & Company, Inc.
Unit cost $1995[1]
Specifications (Standard)
Weight 3.60 kg (7.94 lb)[1]
Length 832 mm (32.75 in) (collapsed)
910 mm (36 in) (extended)[1]
Barrel length 409 mm (16.12 in)[1]
Width 64 mm (2.5 in)[1]
Height 197 mm (7.75 in)[1]


5.56 NATO[1]

6.8mm Remington SPC (upper only)[1]
Barrels 1:230 millimetres (9 in) Right Hand twist
Action Gas-operated, rotating bolt
Feed system STANAG magazine
Sights Folding Iron Sight

The SR-556 is a semi-automatic rifle carbine manufactured by U.S. firearms company Sturm, Ruger & Company, Inc. The rifle was introduced in 2009, marking Ruger's entry into the popular AR-15 market.[2] It is one of several new AR-15 platform rifles to utilize gas piston operation.


The rifle features a patent-pending, "two stage" piston mechanism as opposed to the standard AR-15 direct impingement system. 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 hider is similar to Ruger's AC-556 and Mini-14GB.[3]

The rifle includes a number of other manufacturer's parts such as a Troy Industries railed handguard and Samson folding iron sights, a Hogue rubberized pistol grip, and three Magpul PMAG 30-round 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 assault rifle laws. The barrel is 409 millimetres (16.12 in), chrome lined, and features a six groove, right hand, 1:230 millimetres (9 in) twist.[2]

In August 2010, Ruger announced that the rifle would be offered in the 6.8mm Remington SPC cartridge.[4]

Firing Ruger SR-556 Semi-Automatic Rifle
Adjustable Gas Key on Ruger SR-556 piston rifle
Elements of Ruger SR-556 gas system
Top- Bolt and carrier for Ruger SR-556 gas piston rifleLower- Bolt and carrier for direct impingement AR 15 Rifle.


On September 29th, 2014 Ruger announced the AR-556, a variant that utilizes traditional DI action and introduces a rear flip up sight similar to Magpul BIUS. Pricing suggests that it's intended to compete with other entry level AR-15s such as the S&W M&P-15 Sport.

Ruger SR-556E with Bushnell red dot sight.
  • SR-556FB, standard model
  • SR-556SC, state compliant
  • SR-556C, carbine
  • SR-556CLA, carbine lightweight adaptable
  • SR-556E, essential (discontinued)
  • SR-556ESC, essential state compliant (discontinued)
  • SR-556VT, varmint (discontinued)
  • SR-556/6.8, 6.8 SPC (discontinued)


Ruger's introduction of the SR-556 was met with some criticism for its high price tag (US$2,000) and its weight. Ruger addressed these shortcomings by introducing a lighter and less expensive rifle, the SR-556E.[5]


  1. ^ a b c d e f g h "Ruger SR-556". Sturm, Ruger, and Co., Inc. Retrieved 9 December 2012. 
  2. ^ a b Gilbert, Glenn M., Ruger's SR-556: Ready To Run, Right Out Of The Box, American Rifleman, October 2009
  3. ^ Sweeney, Patrick (2010). "The Ruger SR-556". Gun Digest Book of the AR-15. Gun Digest Books. p. 131. ISBN 978-1-4402-1376-2. 
  4. ^
  5. ^ Cumpston, Mike. "Ruger's SR-556E 5.56mm NATO". Guns 51 (12): 56. 

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