The CZ 512 is an entirely new semi-auto rimfire rifle from CZ. The modular design is easily maintained, requiring only a coin as a tool for field stripping. The action of the 512 is composed of an aluminum alloy upper receiver that secures the barrel and bolt assembly and a fiberglass reinforced polymer lower half that houses the trigger mechanism and detachable magazine. The 512 shares the same magazines and scope rings with the CZ 455 making it the perfect companion to your bolt-action rifle. cal: .22 LR/.22 WMR, stock/finish: Wood/Blue. Dual guide rods for smooth operation and superior reliability. Accurate hammer forged CZ barrel. Adjustable sights. Integral 11mm dovetail for easy mounting of optics.