I have a TC Grey Hawk .50 cal with a stainless barrel and recently removed my scope from it and reinstalled the rear iron sight. There was an aluminum bar screwed to the barrel on which the stainless scope mount was screwed to. The barrel now has some light pitting where this aluminum base sat. I cleaned most of the gunk off the barrel with the rough side of a sponge and hot soapy water but now want to clean up the gunk in the pitting so it does not look so bad. I'd like to use a chemical/solvent to do this that will not hurt the stainless barrel....does anyone have any idea on what to use? Thanks in advance.