The late Ken Eyster who did a lot of custom choke & pattern regulation work for competition shooters would only evaluate patterns shot from well fouled barrels & felt that unfouled bbls
didn't produce optimum patterns.
I don't know if he was correct on this & any of my guns( hunting or competition) w/unchromed bbls always get the bbls wiped out at the end of the day.
For what it's worth, I have more "mystery misses" on grouse than any other bird so now I can add clean bbs to my list of excuses after the dog looks up at me in disgust.
