Just last week I had a similar experience with my new to me 7x57. Every shot caused the bolt to stck with factory ammo. They were 140 grain Sellier and Bellot round nose. I was more concerned about them being rather bland. But they actually had some noticeably strong recoil, and like I said, the bolt stuck on every shot. However, there were no flattened primers. I'll reload the cases and use a book recipe and see what happens. They're made in the Czech Republic but I've had nothing but good experiences with any ammo from there. This is a newly built rifle, assembled from a Zastava Charles Daly Commercial 98. My gun smith did the work and he's done several rifles for me and the only hitch I've had was my .257 Improved which was a feeding problem which I solved by relieving a little metal off the inside of the claw extractor. Otherwise I've had good experiences with his work. I'll see how it handles my hand loads.
