Can anyone tell me how to clean off the black markings on the side of my titanium 329pd cylinder up near the front. They appeard after firing the gun for the first time and are only getting worse. I have tried many products with no results......................................................................................................I finally found a cure for getting it clean, liqiud Brasso rubbed on with a fine-finishing steelwool pad. Now it looks new again....I now need to find a coating of some kind that I can apply to keep the black markings from coming back after I fire the gun again, any suggestions would be greatfully appreciated.