I recently think I did something stupid. This in itself isn't a huge surprise. First things first, the stock cleaning 'nylon brush' doesn't adequately remove deposits on the barrel and ejection port. I used a metal (copper I think) brush..which slightly discolored the gun. I probably should not have done this. I don't know if I accidentally stripped the finish off of the receiver and barrel or if I just rubbed some of the copper off on it. I make sure to keep it lightly oiled...as I don't want it to rust or cause any other issues. What the heck should I use to scrub at this thing in the future? Did I royally screw up, or only slightly? I'll try to post some pics when I get home. Thanks!