I don't know but a gunsmith told me the reason you don't see the high quality bluing that you once did is because the EPA banned one or two of the ingredients necessary to make the bluing that high quality.bownut said:My buddy thinks its the salts they use in the bluing process. There is a product another buddy uses called eezox that he swears works. I never tried it. The VCI (vapor corrosion inhibitor) stuff does work really well though. Helps a lot anyway.