While I was cleaning my 3" model 66-5 and my "butterfingers" were slick with Hoppes, I dropped the cylinder on a brick floor. Nice big scratch in the cylinder -- which nicely matches a couple of the scratches in the frame that it had when I bought it! Oh well! Now I don't worry such much about that gun. Of course, had I done it to my pristine 3" 66-2, you probably would have heard my cries several states away!