I've found that bore butter does not help. A spit patch did, no crud ring. I tried 2 pellets,100 grains pyro. Select,and RS all had crud ring when using bore butter, but did not when using spit patch. Also the groups tighted up from 7-10 inches to 1.5-3 groups Select being the best. I shot 50 to 60 shot today starting with bore butter then ready to hit the local gun shop to see if I could trade for something else. I remembered reading hree that some of you use spit patch so I tried it crud ring disapeard and wow it groups! Thanks.