The Diamondback DB15 is a mil-spec AR-15 semi-automatic rifle chambered in 5.56 NATO. Built to standard AR-15 specifications with forged 7075-T6 receivers, it competes in the commodity AR-15 market. Type: Semi-Auto Rifle Action: Semi-Automatic Caliber: 5.56 NATO Capacity: 30 Year introduced: 2011, USA Weight: 6.2 oz Overall length: 32.5" Status: Active Intended use: Home Defense, Hunting, Competition