Hello GJ2nd,
I had the exact same problem when I tried to use Remington 91/2 large rifle primers. It was the first and last time I ever tried these primers. I was loading for my .243 Winchester. I tried the primers in Winchester, Federal, and Remington brass. I also seat primers with my press, and was using all the pressure I felt I could use. My press is a Lyman T-Mag turret press. I cleaned all my primer pockets and the primers would still not seat deep enough no matter what I did. I reloaded 20 cartridges and when I would chamber them my bolt closed hard. I could see swirl marks on the primer where the bolt face turned against it. I pulled the bullets, dumped the powder, fired the primers in the rifle then reloaded the same cases using Winchester primers with absolutely no high primers. I decided there was possibly a problem with that lot of Remmington primers. They would also fail to seat properly in my .22-250 cases. I've never bought any more Remington 91/2 large rifle primers, and continue to use Winchester large rifle primers for my .243 and .22-250 reloads.
Your post made me curious, so I dug out the Remington primers and miked them. They averaged .131 in height. The Winchester LRP's I have averaged .126 in height. Just a few thousandths can make all the difference.
Coyote 6974
