All RCBS Seater Dies have a built-in roll or taper crimp as appropriate for the particular caliber. To seat bullets without crimping, simply unscrew the die until the crimp ring no longer engages the case mouth.Notes: A Bullet Seater is used to push (seat) the bullet down into the case to a specific depth and is found in the Seating die. Bullet depth is adjusted by screwing the seating stem in and out of the die body.