The subtle radius of each shell holder mouth ensures smooth and reliable functioning. The retainer spring is designed to stay in place when inserting cases into the shell plate. Shell plates for Lock-N-Load AP and Pro-Jector are available to fit most calibers. Each shell plate will also hold additional calibers with the same case head dimensions.Specifications and Features:Cartridge: 50 Action ExpressCountry of Origin: United States of AmericaExtended: NoMaterial: SteelPress Fit: Hornady Lock-N-Load AP