While normally JB bore paste will remove the surface rust from your rifle, I also have a "stained" CVA Staghorn in nickel finish. I tried about everything to get that dull stain out and finally gave up. I live with it. The rifle shoots well and the small stain I guess is all part of the fact the rifle is used and not sitting on a shelf somewhere. I never tried that stuff nimrodder suggested. Let me know if it works.