Knight's Armament Company SR-15 with the improved E3 bolt and internal ambidextrous bolt catch, used by multiple military and SOF units. Type: Rifle Action: Semi-Automatic Caliber: 5.56x45mm NATO Capacity: 30 Year introduced: 2015, USA Weight: 70 oz Overall length: 35.5" Status: Active Military use: Yes Intended use: Military, Law Enforcement, Tactical