Thanks Old Fuff. I can see the steel liner in the barrel, but I do not see any tell tale transition lines in the cylinder.
I called S&W they said bronze brushes are ok, not to use stainless steel.
Even so, I cannot get that firing ring of carbon and crud out of the chambers which corresponds with the case mouths. I used a bronze brush and could not get it to budge. I wonder if there is a better way to get that out of there. Same for the flash on the front of the cylinder, I got a lot of it off, but much remains.
Suggestions?