Ruger SR-556SC 5.56 NATO Semi-Automatic Rifle – Discontinued State-Compliant Piston-Driven AR-15
The Ruger SR-556SC combines the brand’s proven short-stroke piston system with a low-production, state-compliant configuration. Built around a cold hammer forged, chrome-lined barrel and a 4-position adjustable gas regulator, this discontinued variant delivers the reliability SR-556 rifles are known for, without the factory flash hider. Collectors value the SC model for its limited run and hard-to-find status, while shooters appreciate its premium Troy quad rail, chrome-plated bolt carrier group, and Ruger flip-up sights.
Condition
Overall Condition: Very good condition, showing only light, superficial signs of prior handling or use.
Bore Condition: Excellent – Clean, mirror finish, no signs of wear.
Bore Rifling: Excellent – Sharp lands and grooves.
Specific Condition Notes: The rifle shows minimal handling marks, and the bore remains bright and clean.
What’s Included
- Original Ruger factory cardboard box (Model 05904 label)
- Ruger SR-556 instruction manual
- 1× 10-round Ruger steel STANAG-pattern magazine
- Picatinny rail cover set
The SR-556SC omits the flash hider to meet certain state regulations and features a non-threaded/plain muzzle. The 16.12-inch barrel is machined from 41V45 steel, cold hammer forged for strength, chrome-lined for longevity, and paired with a 1:9" RH twist to stabilize common 55- to 62-grain ammunition.
Ruger’s chrome-plated bolt carrier, piston, and transfer rod minimize fouling and simplify cleaning. The 4-position adjustable gas regulator lets the shooter fine-tune cycling for varying loads or suppressed use, delivering a cleaner, cooler-running action than direct-impingement platforms.
Both upper and lower receivers are forged from 7075-T6 aluminum and finished in durable black hard-coat anodizing. A premium Troy Industries aluminum quad rail provides continuous Picatinny slots at 12, 3, 6, and 9 o’clock for mounting accessories. Ruger-branded flip-up iron sights fold flat when not in use and deploy quickly when needed.
A telescoping polymer stock, Mil-Spec receiver extension, and standard pistol grip round out the furniture, keeping the rifle light and adaptable. The SC variant’s limited production and discontinued status make it a desirable piece for Ruger collectors and AR-15 enthusiasts alike.