RCBS Cowboy dies are built to slightly different dimensions than the regular dies to allow optimum sizing, expanding, seating and crimping needed to load great lead bullet ammo. In keeping with the spirit of the game, Cowboy dies even look different. Instead of the satin steel finish on the other RCBS dies, Cowboy dies have a "case-hardened" look.
RCBS Shellholder #20 required for Pro2000 Press, sold separately.