I bought 5,000 small pistol primer brass the first time I got brass for my .45, with the expectation of spending less on primers.
Bad decision, at least for me.
I use a progressive press, so there was big problems when large pistol primer brass from the range that got mixed in wit my small pistol primer brass.
Sorting the two apart is a nightmare, because you have to inspect every piece of brass in great detail to determine primer pocket size before loading.
It was too much of a hastle for me in the end, I sorted them out one final time and sold all my small pistol primer .45, sticking with the more common large pistol primer brass.
It's just a PITA if you ask me.