Well, the rifling is a touch more visible now. I don't know if I can get it much better. It looks as though the barrel was shot heavily AFTER the pitting had started. I made a foul-out system as a last resort and I have to admit that had I not seen it in action, I would not believe something could work so well on lead! I didn't have the o-rings, solvent or stainless rod, so I melted hot glue in 3 rings around a brass cleaning rod, plugged the bore with hot glue and a little kleenex stopper to keep the glue from filling the bore and went with an 11V dc phone adapter. I started with acetone and brasso then ended up using vinegar and acetone. I snipped the jack off the adapter and wired positive to the barrel and negative to the rod ( before filling with liquid, I used a meter to check for lack of continuity).......bubbling black goo was the result! Over and over I emptied the barrel and scrubbed the lead deposits off the rod. When the liquid turned from black to rusty I figured it was time to stop! Now I'll try conventional scrubbing, but man, that system really works! Thanks to everyone for the suggestions too.