I am far from being a gas expert but I have seen this issue. It was from running hot loads in a DPMS LR308. I believe a couple of things were happening. The biggest issue is that the bolt is moving rearward trying to extract while the brass is still expanded and gripping the walls of the chamber. Turn the gas down some, Inspect the extractor claw for wear, change the spring in your extractor. The DPMS style bolts actually have an o ring that you could buy aftermarket. It goes where the extractor spring sits to limit the amount the extractor moves.

I am betting the setting will be somewhere between 4 and 10 clicks off of closed.


I would consider turning the gas down until it no longer catches the magazine when empty. Then turn it back up a notch or two. Try not to run really hot ammo or risk premature wear on the lug matting surfaces.