Favorite powders for this cartridge, such as H110 or W296, require a very firm, normally roll, crimp. I have outstanding results using a Lee Factory crimp die for 454, 357, 38 sp., 45 acp, and 223 rounds. If you crimp too much and form a bulge, the Lee Factory crimp die will resize the (straight-walled handgun) round as it leaves the die so that it will function well in the weapon. Follow the instructions that come with the die and you should have no problems. Enjoy your 454!