A big Plus one on Ed's Red...it's all I've used in my guns for over ten years...was developed by Ed Harris, long time Ruger engineer, NRA Rifleman "Dope Bag" contributer. He consulted with an organic chemist to re-engineer the old Frankford arsenal cleaning solution. The impetus for his work was his involvement in a large hi-power rifle team, and its subsequent needs for a large volume of cleaning solvent...a cost saving measure...
My use of Ed's Red has eased my leading issues in several long and short guns when large quanitities of lead alloy bullets were shot. It seemed to 'condition' the bore in my experience. While not a copper remover, it does a great job on all forms of burnt powder residue.
BTW, Ed allows that turpentine can be used instead of the mineral spirits, and that a small amount of lanoline can be added for longer term storage...makes it stick to the metal and reduces run off. Do a search and check out his remarks on its use.
Best Regards, Rodfac