I am new here and looking for some help. I love the AR guns and decided to buy one of these new platform guns. I love it being a 308. I did the break in according to DPMS and it didn't like any of the surplus ammo. I tried the Federal gold match 168 and bingo, the gun likes it. I went to the Hodgdon loading manual and started loading for it. I have looked all over the internet and trying to gather information about loading for these guns. I loaded some medium powder loads using the H8208. Backing up a little. Shooting the Federal match, the primers showed a little distortion. With the medium powder loads, there was cratering of the primers. Am I doing something wrong? All help would be appreciated.