Ruger's piston-operated AR-10-pattern rifle chambered in 7.62x51mm NATO. Built on an enlarged SR-556-style two-stage piston system with a 16.12-inch cold hammer-forged barrel. Accepted DPMS-pattern LR-308 magazines. Type: Semi-Auto Rifle Action: Piston-Operated Caliber: 7.62x51mm Capacity: 20 Year introduced: 2013, USA Weight: 8.6 oz Overall length: 36.2" Status: Discontinued Intended use: Range, Hunting, Patrol