Ruger SR-556 5.56mm NATO Piston-Driven AR-15, 16.12 in Chrome-Lined CHF Barrel, Troy Quad-Rail, Folding Sights (2015)
This 2015 Ruger SR-556 stands out for its short-stroke, two-stage gas piston system with a 4-position adjustable regulator, robust cold hammer forged chrome-lined barrel, and high-quality Troy free-float quad-rail. It features a flat-top A3 upper with T-marked rail, folding iron sights, and a chrome-plated bolt carrier with the Ruger eagle logo. Offered in excellent condition, it includes a Magpul sling, UTG bipod, and a Magpul PMAG.
Condition
Overall Condition: Excellent condition, showing only faint signs of any prior use or handling.
Bore Overall Condition: Excellent - Clean, mirror finish, no signs of wear.
Bore Rifling: Excellent Rifling - Sharp lands and grooves.
Specific Condition Notes: This rifle shows minimal markings from prior handling and use. The bore is bright and clean. See photos for full details.
What's Included
- UTG rail-mounted bipod (installed)
- Magpul two-point web sling (installed)
- One 30-round Magpul PMAG GEN M2 MOE magazine (5.56x45, polymer)
The SR-556 uses a short-stroke, two-stage gas piston system with a 4-position adjustable regulator that includes a 0/off setting. This piston-driven design is a defining feature of the model and is paired with a chrome-plated bolt carrier marked with the Ruger eagle.
Its 16.12 in barrel is cold hammer forged and chrome-lined, configured with a 1:9 twist and capped with an A2-pattern birdcage flash suppressor. The barrel is threaded, and the chambering is 5.56mm NATO.
The rifle is built on an aluminum flat-top A3 upper with a numbered T-marked Picatinny rail (T4–T36). The Troy free-float quad-rail handguard is aluminum with numbered slots and includes Ruger/Troy-marked rail covers.
Folding sights are included: a folding front sight on the gas block and a folding aperture rear sight, with the rear base marked "Made in USA." The manual safety selector is present, and capacity is 30+1.
Furniture and controls include a telescoping, adjustable stock and a rubberized finger-groove pistol grip with Ruger medallion. Length of pull is 14.0. This rifle comes with an installed Magpul two-point web sling and an installed UTG bipod.