CZ teamed up with ATI to develop a tactical chassis for the 512 semi-automatic rifle. It has a 16.5" barrel with 1/2x28 muzzle threads, a top Picatinny rail, 6-position buttstock with adjustable comb height, and features a higher magazine capacity than the standard gun. The 512's action is comprised of an aluminum alloy upper receiver, which secures the barrel and bolt assembly, and a fiberglass-reinforced polymer lower half that houses the trigger mechanism and the magazine well. One of the best features of the 512 platform is that it uses the same reliable single-stack mags as the 455.