The Hornady Shell Holder is made to help with the reloading of different caliber cartridges including .380 ACP .221 Remington Fireball 6mm TCU .222 Remington Magnum 7x47mm Helm .20 Tactical .204 Ruger and others. This shell holder is precision machined from solid steel followed by being heat treated. The outcome is a press that operates flawlessly.This particular shell holder is manufactured to fit all accessories manufactured by Hornady including the Handheld Priming Tool and Cam-Lock Case Trimmer. However this shell holder is also made to fit most brands of presses on the market today.