Originally Posted By: DennyrMore than likely sizing die set up problems.
Originally Posted By: Jason50calI set it up for just a lil cam over like I do most of my hunting rifles. Gonna try just bumping the shoulder back like I do on my BR rifles
Do you have a way of measuring how much you are setting the shoulders back? That maybe should be step one. Measure a few pcs of fired brass to get an idea what the chamber headspace measures (brass expands to conform to the chamber when fired, but then contracts a little when the pressure subsides). Does fired brass chamber ok unsized? If so, maybe just try neck sizing some by backing the die out so it just sizes the neck partially to hold the bullet. That should eliminate any headspace issues from oversizing. Also, ck to see if the primers are being seated too deep - could be that the primer pockets are deep from new? Maybe try other higher primers as a test if the headspace attempts dont help?
Id guess you are oversizing them. Took me a while to get away from the "screw it down till it cams over" way of setting the sizing die up. 2 different rifles in the same caliber ended that - chambers were quite different in headspace. Had to set the die diff for each. Being able to measure that diff, and not sizing the brass at all when not needed saves wear and tear on you and the brass too.