I've been reloading for 30 years, and just bought my first progressive, an XL650 on Friday. Got it set up Friday night and after a few hundred rounds of smooth .45 loading, I put in another bag of .45 once fired I had bought at the local gun show. I had no idea that they made small primer in .45 - almost 1/2 of this brass was small primer. The first one, I tried to force it and had the large primer blow. First time I've had a primer go off in 30 years. Scared the crap out of me as the press was littered with granules of titegroup. Took me a little while to figure out what the problem was. I'm certainly going to ask from now on and make sure I only buy large primer brass.