manufacturers offer the chambering. In the United States Remington continued to offer the .222 Remington Magnum in a couple of target and varmint rifle models for many years, but currently there are no commercial manufacturers in the U.S. either of rifles or ammunition in .222 Remington Magnum other than Cooper Firearms of Montana. For many .222 Magnum shooters handloading of this cartridge provides ammunition, using components otherwise available for the other more popular .22 centrefire rounds. The .222 Remington Magnum cartridge case became the parent case for a new development introduced in 2004, the .204 Ruger. The .204 Ruger is based on the .222 Remington Magnum case necked down to hold a .20 caliber (5 mm) bullet. See also List of rifle cartridges 5 mm caliber References Speer Reloading Manual #11, Omark Industries, Inc., 1987 Cartridge Dimensions External links .222 Remington and .222 Rem Mag at Chuck Hawks Pistol and rifle cartridges Remington Magnum rifle cartridges