The surface finish of the Bushmaster rifle - all mil-spec hard anodize on the aluminum or manganese phosphate on the steel parts - is slightly textured or "matte finished" so that it won't reflect light - a military necessity. Here are a few tips on maintaining this matte finish.
FIRST: USE ONLY BLACK RAGS on the outside of your rifle. Black t-shirts are great for this. A white or red rag or shop towel will rub into the matte textured surface and leave blotches. If this happens, use a Teflon based oil to remove blotches. There is a clear nickel acetate sealant applied over the anodizing and the steel parts in the rifle are also final finished in nickel acetate. Some solvents in gun cleaning solutions will attack nickel finishes, so read the label on your solvent to be sure you won't damage that surface finish.
SECOND: Get a non-drying motor oil. Any non-drying motor oil will do, as long as it doesn't have additives that might attack the nickel acetate sealant that we apply as a final protective coating. Believe it or not, non-drying motor oil leaves a great looking finish.