I am selling my Savage 270 online so I am trying to get my gun clean as a whistle for this guy, but I am having some trouble with the inside of the barrel. I have cleaned it up and down many times with Sweets 7.62 and the blue has even stopped coming out. So what's the problem you ask? When I look down the end of the barrel, I can still clearly see copper in 2 of the grooves at the end. Any ideas on how I can get it out of there? Or should I just leave it? This is my first and only online sale/buy so far and I would really like to not screw this guy over by selling him a dirty gun. Would you be upset if you bought a used gun online and the barrel had some copper fouling in it? I feel like I would be.