Lee's 458 socom factory crimp die crimps the bullet in place more firmly than any other tool.A firm crimp improves accuracy because pressure must build to a higher level before the bullet begins to move.This higher start pressure insures a more uniform pressure curve and less velocity variation.Type: Factory Crimp Pistol DieCaliber: 458 SOCOMDie Type: CrimpDie Series: Factory CrimpIn Set: 1Shell Holder Cap: No