Some Flitz will rub them right off, and I'll occasionally use it. But my revolvers have carbon rings more often than not.
I had owned my 686 for 20 years when I read about the Flitz product here on TFL forums, and how well it worked to remove the carbon ring from the face of my stainless revolver cylinder, so I bought a tube of it and followed the directions.
The cylinder face cleaned up
beautifully and it looked like it did back when I first bought it. It was really great looking.
First range trip out afterward and it came back looking like it always does, with the carbon rings.
The more I thought about it and the more I looked in to Flitz, the more I realized that it was an abrasive. A mild abrasive, perhaps, but still an abrasive. Using that was taking the carbon rings off my cylinder face... but was it taking off an ultra-thin bit of my cylinder face? And what was the chance that if I
was doing this, was I doing it evenly? (unpossible, especially with
me doing it)
The flash gap in a revolver is critical and though it may be slight or even less than slight, seems to me that taking an abrasive to the cylinder face was a
bad idea.
So I never did it again, and don't see me doing it again unless I find a cylinder that is binding due to something built up on the cylinder face.