I took a sharpie and colored the face of the receiver and barrel nut, I threaded the barrel into the action without the recoil lug and tightened the nut by hand holding the receiver in one had and the nut in the other. I tightened, then loosened, then did it again and took it back out. Here is what it looks like:



The barrel nut was pretty even all the way around except for one small area. Sorry, but this is about the best picture of it I can get:



So going by the contact pattern, it might could be the face was not trued correctly, which also makes me wonder about the bolt lugs in the receiver if they were faced at the same time as the front of the receiver. It looks like there is better contact on the left than on the right, which in theory, could push the barrel right once torqued.