after examining this as thoroughly as I could, to include having the manufacturer look at it. I really don't know. I lean towards a bad barrel. But can admit, that I am biased against Black hole weaponry, because of my dealings with the owner over this. Upon my initial contact with him. I only present the facts and lead with it could have been something I did. in dealing with him, he was less then pleasant, and would not even entertain the possibility of a defective barrel. All he did was talk up how brilliant he was because of his barrel design. To include telling me that his barrels were so good because they would still work great with the exact scenario I hadgunfan2 wrote:An oddity to say the least! Might just have been a funky barrel!
One of his technicians that examined the barrel was more pleasant to talk to, but his "answer" was the cast bullets, not the powder coated ones, but plain cast and lubed could have been the culprit, again
my conventionally rifled 300blk barrels have no issues, after thousands of rounds of cast, powder coated and jacketed. So there is that.