I got my first pistol, a gen 4 g19. I never wanted one until I handled every other gun then picked it up. I was sold. I've only put one magazine through it, and have cleaned it with hoppe's no. 9. There are still lines of copper on the rifling in the barrel. Is it wrong to just leave it. I don't want to scrub it or anything if i don't have to. If it ain't broke, don't fix it. Thanks.