ORIGINAL: eldeguello


I certainly could be wrong about this, but it is possible that the problem is due to over-torquing the barrel nut so that when the barrel gets hot, things expand and relax to the point that the barrel starts pointing somewhere else than it did when cold. Try it again with the barrel nut just hand-tight, and see what happens.

An alternative would be to let the barrel get completely cooled off before firing the next shot. This might be better anyway, since it is generally where the first shot from a cold, clean barrel goes that determines if you will be eating venison or tail feathers!