The Colt M16A2 is the military-service-rifle configuration adopted by the U.S. military in 1982 with a heavy barrel, fixed A2 stock, A2 pistol grip, and improved 1:7 twist rate. Civilian semi-auto versions marked M16A2 are valuable collector pieces. Type: Semi-Auto Rifle Action: Gas-Operated Caliber: 5.56x45mm Capacity: 30 Year introduced: 1982, USA Weight: 8.7 oz Overall length: 39.5" Status: Discontinued Military use: Yes Intended use: Military, Collecting