hey. dumb question to follow. i'm very new to revolvers (this is my first). i was cleaning my new s&w j frame, and it was going smooth and easy. until i noticed all this crud around my cylinder. i never really looked before i shot it, so i was wondering if this would be considered clean? i scrubbed the tar out of it with standard solvent and soft toothbrush, but i couldn't get anymore of this off. is this normal? if not, is there a better way to clean this part of the cylinder? thanks for any help.