BCM Cold Hammer Forged 14.5-inch barrel upper receiver assembly. Government profile barrel with mid-length gas system. Pinned and welded muzzle device. Built to mil-spec. Type: Rifle Action: Semi-Auto Caliber: 5.56 NATO Capacity: 30 Year introduced: 2011, USA Weight: 60 oz Overall length: 31.5" Status: Active Intended use: Duty, Defense, Patrol