The burr is in the middle of the barrel. It looked like a spiraled piece of metal like you would get from drilling in a drill press, about an 1/8" to 3/16" long and looked about 3 times longer than wide. Hooked on a cleaning rag the first time. Pushed a brass bristle down the barrel, caught on it and half way folded it into the rifling groove, but not all the way . You can still see it quite easily but the point is it is attached pretty good. It catches the brass bristles no pretty good either pushing or pulling. Im afraid if I shoot it it will burr a groove all the way down the barrel or fold completely into the rifling groove only to come out some time in the future and then still scar the barrel. If I knew the mfg I could send it in to get removed.