[Milkmaster]

I retreived my Dad's old shotgun the other day and found he had not cleaned it in a LONG time. I cleaned it with the normal gun powder solvent, wd40 , and the gun oil. There is a patch of rust right after where the shell sits that I would like to clean better.. I know the pitting will stay, but I want the rust stopped and get no worse. What is the best thing to use and method? Suggestions are appreciated.

[dfariswheel]

Wrap a piece of #0000 Steel wool around a bronze shotgun bore brush.

Chuck the cleaning rod in an electric drill and put the brush on the rod.
Running the drill at medium speeds, polish out the entire bore and chamber, keeping the brush constantly moving.

When the rust is gone and the bore is bright and shiny, use patches and solvent to clean the bore of steel wool particles and dirt.
Then apply a thin coat of your favorite lube.

Smooth bores like shotguns are the ONLY guns you should ever do this on.
This is an accepted method of cleaning rust and fouling from a badly neglected shotgun barrel but WILL damage and ruin a rifled barrel.
SHOTGUNS ONLY.

[Milkmaster]

I took a 9mm bore brush and wrapped it with steel wool as suggested. I wrapped enough on it to make a somewhat tight fit on the 20ga barrell. The cleaning took me about 10 minutes of back and forth while turning with my dewalt drill. The bore came out clean as a whistle. I was very pleased with the results. Thanks for the advice!