Strange blemish under crane on 642

[TheBigFellow]

I've had this for well over a year now. At the time, no lock 642's were somewhat of a rarity around my area so when I found this one at a great price I didn't check it over as best I could. It wasn't till a few days after I had purchased it that I noticed this strange mark under the crane.

At first I was worried it was a crack, knowing the history of Airweights and overtightened barrels, but besides it being in an unorthodox place for a crack, the blemish doesn't seem to go through the frame, just on the surface. I decided to keep my eye on it and see if it became a problem. Over a year later and 1,000 rnds down range, nothings changed.

I'm still left wondering what it is though? Any ideas?

 

[s&wchad]

That’s just a machining mark, it's nothing to be concerned about. When frames crack, they crack directly under the barrel (6 o'clock) in the thin spot.

 

[Tyrod]

I'd be more concerned with those dots. Your revolver may have the black plague!

 

[TheBigFellow]

That’s just a machining mark, it's nothing to be concerned about.

I had my inclinations but wanted to be sure. Out of the hundreds of pictures I've seen I'd never seen a mark like that.

I'd be more concerned with those dots. Your revolver may have the black plague!

Wait, WHAT? You mean yours doesn't have that too?