I have a 8mm barrel that I am real carefull on when and how I clean it. I have noticed recently that there is a spot about 2.5" from the muzzle, that seems to have a very heavy build up of copper. It kind of looks like an AR15 looks right at and past the hole for the gas block on the amount of fouling. It seems to get worse the more rounds that are put throught it. I have to foam it 3-4 times for it to go away. It almost acts like a tight spot right there. You can not feel it when cleanig though. This is chambered in 8x57 and it is a Shaw barrel. Does any one think that the Tubbs final finish might work to smooth out this area? I am not worried about the throat moving out too far as this thing has a very short lead. I have to seat the bullets under what all the books call for by .01". So has anyone had luck with this system?