I've had a Lyman Great Plains, left hand, 54 caliber round baller for about 20 years. I shot it in June and recently put a cloth patch down the bore. It came back very rusty! Now when I put a patch down slowly, there seems to be a rough spot about 2/3 of the way down. I usually clean on returning home after shooting at the range. My routine is remove barrel, remove nipple and clean out screw, put barrel end in a coffee can, pour boiling water through muzzle and by hydraulic action run a patch through the bore several times, change water and repeat. run a small amount of compressed air through nipple opening, when barrel is dry, then bore buttered patch is rammed down the bore. This routine has worked for me since buying the rifle. My questions are: 1. Any way of removing the rust?
2. Is the barrel ruined?