Will Not fit the Western Air Guns Rattler and SideWinder… Diameter: .307, Length: 17mm

Tested with the Airforce .308 Texan Rilfe 855 velocity, 278 Bullet kinetic energy foot pound force (ft/lbf), with a 25 shot count. Meets Texas requirements of 215 ft.lbs of energy for game hunting. Great for target, varmint, hunting game.