BTW - note to self was DON'T MIX primer types on my tiny little loading bench. There was a stack of primers next to my Dillon. The Forster CoAx is to the left of the Dillon. The last time I loaded with the Dillon I loaded 10mm and used large pistol magnum primers.
When I started to load for the 7mm Rem mag I reached for the CCI box, opened it, yup those are big. I hand prime (Sinclair makes a nice tool for that) and the whole time I was hand priming I thought- "weird, these are seating farther down and easier than last time" followed by "I guess the primer pocket is getting loose".
Then, when I decided to load some more rounds for sighters, I picked up a box (both CCI) and opened it to get some more primers. There were too many primers in the box and the pattern of empty holes was different. I checked the size, yup, large rifle magnum so that's good. I primed a few rounds with those and they seated like they always do. The seating difference and the empty hole pattern in the tray was too much to ignore. Sure enough, I had picked up the large pistol magnum primers to load the rifle rounds with. Funny how the brain remembers patterns... I'm glad it did otherwise the misprimed rounds would be waiting for me to go shoot them.