PMC,
Just a thought on your reloading issue. With the tight chamber and the bow where you show it, I've come across something very similar. I'm using small base dies for my .308, which isn't good unless you need them. In my case I was noticing the mouth of the die was so tight it was pushing a wave, just like yours down the sides of the cases.
I backed the dies off to where they only neck size halfway down the neck. It's not optimal, but the cases fit. I was finding that anywhere in between full "cam-over" and where I have them at now for neck sizing, the cases would not re-chamber in the rifle. I reduced the loads even more to prevent ANY brass stretch with the neck sizing, and that seems to be working. It's been a pain in the ass ever since I started with this rifle. Probably more the dies....