Have you ever used Fluid Film?
Fluid film is a spray on anti-corrosion treatment that John Deere uses on their equipment when they ship it overseas. It is fabulous stuff when it comes to stopping rust and even works pretty good at removing rust. I heard about it about 10 years ago and bought a can to use on my guns. I spray it on and wipe the gun down with a rag, it has worked very well, especially on the guns I carry duck hunting. My 870 has been wet so many times that it should be a rusted hulk, but the only rust problem I have with it is on the bolt which runs through the stock. You should buy a can and give it a try, it can be found at most John Deere dealerships.
