My Renegade is the same way, and I'm using 777. I was given this gun a few years ago by somebody who was less than diligent about cleaning it immediately after shooting. The price was right and it shoots good enough, so I'm not really concerned about it. But like you, I could run patch after patch and still have some marks on them. After the 2nd or 3rd patch it is very light, but I went through 8 dry patches on my last cleaning before I just called it quits. It shot perfect yesterday at the range, so I'm satisfied dirt or no dirt. If anyone has any pointers to rid the problem, I'm all eyes. Perhaps plugging the nipple, filling the barrel with something, and letting it soak for a while could help. Anybody done that before for a dirty barrel?