Hiya MGM!
Clean the bore as well as you can, then with an undersize jag(maybe .22cal) wrap just enough 0000 steel wool around it to fit the bore snuggly, not tight, you want to be able to run the cleaning rod up and down the bore with just thumb and first finger pressure. Add a few drops of oil to the steel wool and run it up and down the bore a couple of dozen times, then wipe with clean, dry patches. If you feel the dry patches drag where the rust is, run some more clean 0000 steel wool with oil up & down the bore again, then clean as before. Light pitting will not adversely hurt the barrel or it's accuracy.
Hope this helps you!
Clean the bore as well as you can, then with an undersize jag(maybe .22cal) wrap just enough 0000 steel wool around it to fit the bore snuggly, not tight, you want to be able to run the cleaning rod up and down the bore with just thumb and first finger pressure. Add a few drops of oil to the steel wool and run it up and down the bore a couple of dozen times, then wipe with clean, dry patches. If you feel the dry patches drag where the rust is, run some more clean 0000 steel wool with oil up & down the bore again, then clean as before. Light pitting will not adversely hurt the barrel or it's accuracy.
Hope this helps you!