I've done both 45 Colt and 45 ACP. For the 45 ACP cartridge, I used a 40 S&W die to taper the neck and then a 38 die for the final crimp over the mouth. Starting with a 308 or 30-06 case, trim to the length of a loaded SWC round. Run through the 40 die, trim again. I forget the powder/charge, but as i recall, it wasn't that much of a mental exercise to get it to function safely. If your primer backs out, go with more shot.