I noticed some funny little marks on the front edge of the cylinder on my 19-7. When I bought it I assumed it had been placed on a damp surface or something and picked up some tiny water spots. Now I see that all cylinders have the identical mark, evidently caused by the screw-hole in the top strap directly above it. Firing must cause the marks--little perfect circles. I'm guessing that the gasses are bouncing around in that area. I've just never noticed this before on a Smith. No big deal.

Totally Normal, nothing to worry about!

I have noticed it on several S&Ws. Since I do not get worked up over such marks, I never cared. Some, however, dislike the idea of any mark showing use.

Thanks for the replies. I figured it was something like that. I just never noticed it before on this fairly pristine gun.

Hi and first post on this forum. I am new to revolvers and purchased a 627 pc 2 5\8" barrel. I too have the circular deposits on the outside of the cylinder along with what I think are excessive carbon deposits after 50 rounds. I called S&W and they said it is normal. I purchased a M&P 340 CT and do not have any any marks and I do not have excessive carbon on the cylinder or the frame around the cylinder. I took a look at the 627 frame and I believe the rear sight front screw should be flush with the frame. If this turns out to be correct, why would they not make the front hole blind or use the correct length screw? The 340 frame is smooth.

I agree that the screw should be flush with the frame, now that you mention it. That would prevent this little issue.