Gas key solidly in place and staked?
Went to Reno gun show talk to the guy that built the upper, he was not there but a friend of his was, told him the situation, had the bolt with me, he took it apart and replaced the extractor, it works much better, shoots every load that I tried but still has issues with loads with A2520 powder. That particular load shoots groups under 3 inches at 400 yards and is just under max, may carefully increase the powder charge but hate to mess with an accurate load.
