Went Hunting this year on a ATV and I had the gun rack on the front (Just the two pegs that hold it in place). Went through alot more mud and rain than I expected. Well needless to say, I forgot to clean the barrel right away, and noticed when we returned home the rust on the outer part of the barrel. Sprayed WD40 all over the barrel a couple of times and let it soak in good, then I cleaned the rifle a few times. You can see a little rust still on the outside of the barrel, and was wondering what it would take to remove it? Or should I just forget about it and continue hunting?