greetings fellow shooters. Have been reloading for too many years to count but ran into an interesting result Tuesday while shooting. I was load testing a 336 of mine, not a new gun but lightly shot. I was using new starline brass, Hornady 150 roundnose bullets and the following powders 34 to 36 grains RL 15; 33 to 34.5 grains of varget, and 31 to31.5 grains of leverevolution. All of the fired cases show primers backing out a little. Enough to concern me. the last pic is an unfired case. Any suggestions?