Hi rob, I don't do .380 reloading, but do quite a bit of .45 ACP reloading. I always use a Lee factory crimp die as my last reloading step. The factory crimp die resizes the completed round to produce a correct round diameter. Without the factory crimp die many of my .45 ACP would be too diameter oversized to reliability chamber. Using the factory crimp die as my last step guarantees that each of the rounds are the correct size.Having an issue when reloading .380 case is bulging when seating bullets. Please help any ideas. I'm using RCBS carbide reloading dies in a Dillon XL650 press. Please help.