Another method that I used to clean up an old barrel that I bought at Friendship was to make a "patch" of 1,000 grit emery cloth and run that through breech to muzzle several times. Then, about 1/2 inch from the end of the ramrod, wrap the end of the ramrod with teflon tape so that it is a tight fit in the bore. Then, with a slit cut in the ramrod, attach a very thin piece of 1,000 grit emery cloth, (approx. the width the of the groove and about 2 inches long). Then, run the ram rod down the bore, breech to muzzle on each groove until you get the desired feel. If it is deeply pitted, it will still be felt , but not as rough as the start. The pits will always be felt until totally removed. The barrel, I did this on was an orginal from around civil war or before. .54 cal swamped. 7 groove. very rough at first. I had to run a stainless steel brush down it several times first. It now shoots very well with a .535 ball. a little tight but should smooth out over time. "Poor boys got Poor Ways".