Interesting comments about different experiences. I have 2 3d generation colt single action army revolvers , the newest one I bought a little over a year ago, the older one I bought in 1980. I’ve used flitz on both of those guns for the same issue , burned powder and lead deposites on top of the cylinder. The older gun I’ve shot twice a month for the past 20 years and used the polish on the cylinder all this time and I’ve yet to see signs of blueing loss. Even flitz will tell us it does not remove blueing. I think I better call them again in regard to the new blueing on smith revolvers . I’d hate to ruin 2 new guns for the sake of a few marks on the cylinder. Thanks for all your responses .