Update:
I determined that it was in fact gas getting out of the case and into the chamber before the brass expanded. I have done a few things and this problem has gone away.
I had the firing pin bushed by GRE-TAN Riffles, and all of the primer hits are very uniformed and show no pressure signs. Very happy with this work. Shot up to 70 grains of Retumbo and the primers are perfect. No crater, not flatted, pretty nice. Prior to this work, even the lighter loads still had some cratering. If you dont know about this process look up his video on You tube. He did the work for 100$ and had it back to me in 6 weeks.
At the 65.2 load, which is a minimum load according to Berger, it did happen one more time, after the firing pin work and sizing down on my bushing. But I have since bumped up my charge to 69.5 and have shot 30 rounds without an issues with a mix of new and 1x and 2x, fired brass.
Accuracy is good and the speed is very fast 3400 +/- 20 FPS, but the primer pockets are holding well, the bolt lifts fine, and no suit or dented brass. The speed is faster than I like, but this is just a project and I will just keep shooting it until its over.
Thanks for everyone's input.