After a trip back to BCA, the upper shoots and functions great. The buffer would get stuck in the receiver extension when I cycled it by hand and with the first round I fired. I had to separate the upper and lower to get it to release. It had plenty of lube.
When it came back, I put it back on the same lower and it did the same thing. So I used a different lower and it works flawlessly.
The other lower works great with the usual upper (AR57). The 17HMR has a longer buffer, 4.655 inches, with no weight in it. My guess is that the receiver extension on the other lower must be slightly bent that is causing the longer buffer to bind.
I shot 20 rounds through it for a function check without issue. The last 2 were the only ones I shot at a target other than water lillie's. This was from about 25 yards with a borrowed and non-zeroed scope.