Primer pocket uniforming
I use lots of range brass which I pick up along with shells from my own two .45s. As reloading is a hobby, I don't mind taking extra steps to insure clean, functional ammo. After decapping, I wash and tumble my brass, after which I use a primer pocket uniformer (from Sinclair) chucked in a portable drill. Priming has never been easier and all primers are seated to proper depth. My MP .45 does not like even a slightly high primer. You would be surprised at the lack of uniformity in primer pockets, even from the same manufacturer. Primer pocket uniforming is also a foolproof way to find .45 brass with small primer pockets rather than crushing a primer during the primer seating stage on a press.
I'm finding increasing numbers of small pockets which I'm setting aside. When I have enough of them and when I have to change over my Dillon RL 550 to do a run of 9mm, I'll load up a batch of small-pocket .45s at the same time.