Magnum Research Magnum Lite .22 WMR 9+1 19" Black Threaded Barrel, Black Anodized Picatinny Rail Aluminum Receiver, Black Polymer Hogue Over-Molded Stock Magnum Research Magnum Lite Rimfire a patented gas system and block under the barrel that taps a small amount of gas through a orifice hole in the barrel. Features a stainless steel barrel w/threaded muzzle and a Picatinny rail on the receiver. *Note- This rifle is designed to shoot 40 grain and 50 grain ammo ONLY.