i would put my money on an improperly adjusted die. sounds like oversizing causing a bulge in the middle of the case.
.528 on new and .530 sized is normal the chamber is .533
the best fix is to back your die out and reset. first check if your fired brass chambers easily after it is deprimed and if tight then lower your die slowly until your case chambers easily. get a bump gauge and check cases to set proper bump
.528 on new and .530 sized is normal the chamber is .533
the best fix is to back your die out and reset. first check if your fired brass chambers easily after it is deprimed and if tight then lower your die slowly until your case chambers easily. get a bump gauge and check cases to set proper bump