The Spikes Tactical ST-15 5.56 NATO is a usa-made semi-automatic rifle chambered in 5.56 NATO, introduced in 2003. Primary use: sport, military, hunting. Type: Rifle Action: Semi-Automatic Caliber: 5.56 NATO Capacity: 30 Year introduced: 2003, USA Weight: 104 oz Overall length: 43.5" Status: Active Intended use: sport, military, hunting