Hi Griz
About five years ago I tried center punching the hook on an extremely off-face 12 gauge Crescent hammer gun I'd purchased. It put the gun back on face until I shot a round of trap with it, half-ways through the gun was just as shakey as ever. Believe it or not I got the "repair" idea from a gun repair manual. The problem is, all it does is raise the metal along the edge of the bearing surface, leaving no support in the middle. After questioning the board, and getting a mild hand slap from Russ Ruppel, I finally had the hook tig welded and then I hand refitted the hook using a fine toothed file and emery cloth, it really wasn't that hard to do.
AS far as the puch pricks along the water table, that was probably an attempt to tighten up the fit where it locks and tighten up any sideplay wear along the lug. I really doubt that it lifted up the metal enough to make much of a difference, especially if the guns been shot much since it was done.
Steve
