Its been a while since I loaded ammo for my 45 ACP and I acquired a bunch of once fired brass from my cousin who instructs handgun classes. After depriming, tumbling and flaring out the case mouths, I filled my hand primer up with large pistol primers and WTH??? They wouldn't go in. I started looking at the cases and sure enough out of the 400 or 500 cases I had, I only had about 50 that took the large pistol primer. The rest of the cases were made for a small pistol primer. Now I have to be sure to predominately mark the ammo boxes as large and small so I don't have to go through that sorting process again.
So if you didn't know this, beware there are .45 ACP cases with both large and small primer pockets.