Cayugad, I used windex after each shot and a dry patch. I wasn't sure what to expect as far as crud. Never got the crud ring. By the way, I ran out of 777 primers and had some kleenbores to use up. There was no difference in my groups between those two primers. I will still buy more 777 primers...I like them. The kleenbores have a tendency to get a little snug once you get fouling around the breech.