Even if the barrel is pitted, I can't imagine that it would not clean right up with a brass brush and some good bore cleaner.
If I were you, I would just try scrubbing the barrel with a .45 brush (rather than a .40....get a good strong scrub going) and some Hoppes, and getting a hundred rounds through the barrel. Should clean that baby right up! Also, I don't know how you clean your gun. Some people believe in leaving the barrel clean and bone dry. I always will run an oily patch down the barrel after I get it as clean as possible. Then try and get it dry with a clean dry patch. I believe that leaves just enough oil to not make the barrel a dust magnet, or splash oil when shot, but enough to prevent oxidation.
I wouldn't worry about harming the barrel with a larger bore brush. The brush will compress, and brass is very soft compared to the steel in the barrel (hell pretty much any metal is softer than the metal used in any barrel). My die in the wool gun-nut buddy who taught me about hand guns after I got out of the Army (I knew nothing about handguns) always used larger brushes than the caliber of the gun he was cleaning. And there is always something bigger. He would use .44/.45 brushes on his 9mm. He'd use rifle brushes on his big bore pistols. He's somehow get a 9mm brush through is .22s. I never watched him clean his shotguns, but he probably used a rotor-rooter. (He was an extremist at everything...I often wonder if he's still alive :roll: ).
Peace,
D.
