Redding handgun cartridge crimp dies were designed for those who want the best possible crimp. Profile crimp dies provide a tighter more uniform roll type crimp and requires the bullet to be seated to the correct depth in a previous operation. These dies are not for cartridges that headspace on the case mouth.
All progressive die sets are supplied with a profile crimp die (or taper crimp die if the cartridge headspaces on the case mouth) because the best possible crimp is attained after the bullet is seated.
The design of the Redding Profile Crimp Die is an example that came about from an attempt to help silhouette shooters solve the typical “half moon” crimp so prevalent with magnum handgun cartridges. Redding's solution to the problem not only solved the ugly half crimp but proved to tighten groups as well.
