I had a new BC that was "cross threaded". I called customer service and they sent out a new bolt. It would not even start one turn. The threads in the receiver look OK, but something is wrong. If it was a used gun, I would buy a tap and chase the threads. With a new one, they can make it right. I am waiting for a return label to send the whole thing back for repair.
To remove the bolt, I put it in a padded vise. It turned out really hard, but it came out.
The serial number starts with an XH, if anyone is interested.
Chancy Shot