My copper Nemesis clone and my brass Cartel I use Wieman's/Wright's Brass polish, you could even use Brasso if you want, though with Brasso you have to be easier on how you buff copper and silver with its coarse abrasives. Apply, let set and dry, buff with a microfiber cloth, then wipe again with a car chamis, and apply some Turtle Wax paste, and buff that out after drying. Gets the metals nice and sparkling, the turtle wax makes them a bit more slippery, but helps protect the metal from patina longer between polishing, do not apply the turtle wax to pins and threads though.