Originally Posted by nitestalker
Why would a screw extend through a chamber wall? That would be a very serious problem.
The screw hits the barrel thread but does not penetrate the bore. So normally the leak would be negligible, contained by the barrel threads tight in the receiver. I think I was incorrect blaming the trigger guard screw first. A defect in the barrel thread is what really would unseal the chamber.
Why the long screw, I don't get it either. Just a guess, the original Mosin mag screw was prone to walking out, so it was decided to drill a deeper hole, and that the rifle could take it.