It's an autoloader, so I don't think it actually slams aganst the bolt face all that hard. The cases are not being streched perminatly, measuring them after being fired they are not streched. 60 grains of rl15 is the max load although data supports being able to go higher, I have shot 50 or so round of lower grain rounds and not had this problem, They were CCI primers, all this is leading me to the primers being too soft and inertia causing them to push out, also they are not flattening.