OK, here's a winner.

How 'bout some pix?

Also, has anybody examined the "spiral pattern" to determine if it is not stressed metal caused by the RIFLING process itself? Just like the swirl pattern that sometimes exists on old Winchester actions which cannot be measured or felt, and only shows up after many years and a patina?

Depending on how rifling is cut, outward pressure could I suppose exist, especially with a very thin-tubed gun. For it to show the length of the barrel, I suggest this might be investigated. Especially since I cannot conceive of how a full-barrel spiral would exist since the barrel would, for some length, be carrying an already engraved bullet, mono or not. Hence my question in the previous thread.

Oh, my supposition is not based merely on a guess. When I stamp letters on knife blades, the letter can and sometimes does show up on the opposite side of the blade "backwards", even though it cannot be measured with a micrometer OR felt with the hand. This makes me wonder that if the visible osr condition exists, it could be caused by either many bullets or internal stresses laid up by rifling.