Taper Crimp Die 
The taper crimp die is also specially configured to center both the case neck and the case body, thereby aligning the entire cartridge for a more uniform crimp. Dillon Rifle Dies are designed to meet the more rigid requirements for both accuracy and precision demanded by today's marksman. 

A taper crimp die is preferred for loading ammunition intended to be used in semiautomatic firearms with detachable box magazines, and in lever-action firearms with tubular magazines.