The Colt AR-15 SP2 is a transitional model between the original SP1 and later A2-series rifles, featuring a bayonet lug, birdcage flash hider, and forward assist added to the original SP1 design. Marks Colt's first incorporation of military-specification updates into the civilian line. The SP2 retains the 20-inch barrel and fixed A1-style stock of the SP1 with updated furniture. Type: Rifle Action: Semi-Automatic Caliber: 5.56 NATO Capacity: 20 Year introduced: 1975, USA Weight: 6.5 oz Overall length: 39" Status: Discontinued Intended use: Sport Shooting, Collecting