I was cleaning my S&W mod. 36 and noticed a little pit like a center punch would leave right in the center of the corner where the part of the frame below the cylinder meets the part of the frame in front of the cylinder. At first I thought it was left from a piece of shrapnel. I retired one of those H&H (or H&K?) 9 shot. 22's because the cylinder had enough slop that the barrel would shave part of the bullet and spray shrapnel. But, this gun has never done anything like that, and there's NO slop in the cylinder. Then when I was cleaning my mod. 65 I noticed the same mark on it. What do you guys think? I'm leaning toward it being made that way, but can't see what it would be for.