Hmm.
Wonder if it is pre LC contract...
You mean the web is thin?
Or the walls just ahead of the web?
I suspect the crimped primers and ATK taking over the Lake City plant in 2000 happened about the same time.
The web is thin. One or two loads and the primer pocket expands. I check several that I scrapped and some were ok and some were noticeably thinner. I set up my RCBS press mounted primer pocket swage, which uses a punch though the case mouth to push the shell case down onto the "nipple" that swages the crimp into the head. Set up for a normal case some of the big FC cases were a loose fit. If I had a large number of the big FC cases that is how I would segregate the "thin" from the normal.
