I have way too much time on my hands and spend a lot of it cleaning military rifles. Fortunately, most of my surplus arms have decent bores. I have a few that were in need of substantial cleaning and some that never cleaned up. I have found that G.I. bore cleaner, Shooters Choice, J.B. Bore Cleaner, Remington Bore Cleaner and a lead wiping cloth on a brush can often produce great results.

Sometimes the bores were badly pitted and rusted from corrosive ammo or neglect. In those cases it was necessary to rebarrel the rifle. All the best...
Gil

Want to add one emergency item that has helped on the really "crusty" bores: boiling water. Not tap-hot, but a full quart of water at a full rolling boil.

Used a cup at a time through the bore, with a good brass-bursh scrubbing bettween applications. Wear gloves, as it will heat the metal past the comfort zone.

After taht application, there may still be some jacket fouling, but there won't be any rust, preservative, or other fouling. Before the barrel cools, but while still hot, get after the jeacketed fouling with your favorite solvent...they all seem to work better when the steel is hot, and you'll find the jackete material comes out with a lot fewer apoplications of solvent.

Good suggestions.... in particular, I found by accident this weekend that the lead-out cloth (Kleen-Bore brand, I think) removes rust pretty well, as Gil reports. It will take off the bluing as well, so don't get too carried away.

Heat definitely increases the rate of chemical reactions, so even warming the barrel with a hair dryer can speed up the solvents.

Ahhhh - Reminds me of the boot camp days!

After a day on the ranges with the M1, we'd take the barreled actions into the steaming hot showers with us. GI bore cleaner, GI lye soap and GI bristle brushes would clean those pieces right down to the parkerized finish, including the piston rod and gas cylinder! Swab the bores with soap, solvent and bore brushes and you could whistle "Dixie" through them! :D

You guys had hot water and SOAP too ! Boiling water will kill rust as it drives out the oxigen at the rust to metal surfaces ! Other wise you will still have rusting going on with the tinyest bit left in the botom of a small pit which will start rusting again ! You would be suprised at how bad a rusted out barrel can be made to shoot again for hunting groups just by breaking it in again like you would a new barrel ! JAGG