The LWRC REPR MKII (Rapid Engagement Precision Rifle) is a piston-operated AR-10-pattern rifle in 7.62x51mm NATO with a 16.1-inch barrel. It uses LWRC's proprietary short-stroke piston system scaled to the larger .308-pattern receiver for reliable full-power cartridge function. Type: Semi-Auto Rifle Action: Piston-Operated Caliber: 7.62x51mm Capacity: 20 Year introduced: 2014, USA Weight: 9 oz Overall length: 36.5" Status: Active Intended use: Precision, Patrol, Long Range