I remembered this thread fron a while back and had to comment as I had a problem I've never run into before. (Had to do a search to find this post again).
I had Remington #10 caps in my capper and they were perfect for my ROA. I knew I was getting low so recently I bought 2 more tins only this time they were CCI. Dumped a tin in my capper and went back to shooting. Had a heck of a time getting them seated properly. I thought, what the heck?
Had several misfires. I thought the nipples were fouled enough he caps just didn't want to seat. When I cleaned the pistol, I had one of the clean nipples out and checked it with a cap for fit. After trying several caps from this tin, none fit correctly and were all too tight. I set them aside and tried several caps from the second tin I bought FROM THE SAME BATCH. They fit perfectly. I got my mic out and double checked nipple and both tins of caps. The 2 tins averaged over .010 difference! Sorry, but that is a LOT!
In disgust I threw the undersized caps away. Quality control issue I'd have to say.
BUYER BEWARE. I've never had to do this before but from now on, when I need caps, I'll take one nipple with me and check several caps from a tin to be sure they're correct.