The Dillon Precision Crimp Dieis specially configured to center both the case neck and the case body, thereby aligning the entire cartridge for a more uniform crimp. Dillon Dies are designed to meet the more rigid requirements for both accuracy and precision demanded by today's marksman. NOTE: All Dillon Pistol Die sets include our sizer/ decap die, seat die and a separate crimp die (taper crimp for autos, accu-crimp for revolvers).