Iosso GUNBRITE is safe for use on factory blued, stainless steel, chrome, and nickel guns. It removes powder fouling, surface rust, tarnish, and discoloration from the barrel and stubborn black carbon burn from the face of the cylinder. The cleaner leaves behind a non-oily protective coating that resists fingerprinting and moisture. Also, great for badges, buckles, buttons, knives, etc.