"Colt is the original manufacturer of the M16 rifle and M4 carbine used by the US Armed Forces; and through those 40+ years of experience has gained a wealth of knowledge in producing reliable weapons that function in harsh environments. The Colt AR15A4 Semi-Auto Rifle resembles the original full-size AR-15 with an A2 fixed stock, A2 pistol grip, A2 fixed front sight, and a 20"" barrel, though it has a detachable carry handle. The upper receiver has a flat top with a Picatinny rail for attaching optional aftermarket sights. The AR15A4 operates with a direct impingement gas operating system with a rotating locking bolt. The chrome-lined barrel with a 1:7"" twist stabilizes a wide range of bullet weights, including the heavy-for-caliber bullets used for hunting and long-range shooting. The rifle features an ambidextrous safety and a single stage trigger. The upper and lower receiver is made of 7075-T6 aluminum, with a black hardcoat anodized finish. The 4150 CMV steel barrel features a manganese phosphate finish. The Colt AR15A4 Semi-Auto Rifle operates with either 5.56 NATO or .223 Remington ammunition. Comes with one 30-round PMAG magazine. Reminiscent of original AR-15 A2 fixed stock, and A2 pistol grip Flat top receiver with detachable carry handle Black hardcoat anodized finished receivers Uses both 5.56 NATO and .223 ammo Chrome lined barrel with 1:7"" twist Direct impingement gas system Includes one 30-round magazine"