Redding 6.5mm Creedmoor National Match Taper Crimp Dies were designed for handgun cartridges which headspace on the case mouth in which conventional roll crimping is undesirable. Also available for some revolver and bottleneck rifle cartridges, for those who prefer the uniformity of a taper crimp. Notes: A taper crimp gently tapers tighter and tighter to hold the bullet in place. This doesn’t work the case mouth as hard as the roll crimp and it doesn’t affect the overall length of the cartridge. Mfg: Redding