NAAA(R) .22 Magnum Holster Grip Rimfire Mini Revolver with .22LR Conversion Cylinder As with every NAA Mini Revolver, the hammer need not rest on an empty chamber. Using the original half-way notch cylinder, the hammer may rest safely and securely without chance of accidental discharge. North American ArmsA(R)'s .22 Magnum can be used with all popular .22 Magnum ammunition, including .22 Magnum shot shells (called Snake Shot by some manufacturers). And with the included .22LR Conversion Cylinder, it's bound to become your favorite plinker.