I have used RIG gun grease for over 45 years with no rust problems. Brownells has it. You can use it for light rust removal also. Rub the spot with some RIG on a rough rag. I have had good luck with the 0000 steel wool and Hoppes #9 for removal of rust. I put some on the steel wool and rub lightly, then let set over night. It takes several times, but it has worked for me.