Turns out it WAS the extractor like SS said originally.
I started getting jams right away, inspected the cases and could see the extractor marks were off. I switched out the BCG and it started working fine. I thought originally when I went out and function tested it, that I tried a different BCG but I hadn't, I had just tried it on a different lower. Live and learn right?
I fired some factory 110gr Hornady Vmax, those suckers have some pop!
Then I tried some reloads, 150 fmj and 125 Nosler. I got my red dot dialed in and the 125s were shooting great.
On some reloads the bolt wouldn't seat all the way so I really need to get one of those gauges to check those. Other than that it feels good to have this bad boy operating.
This was a couple groups with the 125s. Picture should be vertical.
17 gr of 4227.