Rig Gun grease. My buddy put three coats on a 10/22 that he had removed the blue and polished. He rubbed in each coat of Rig until you couldn't feel it. He left it in his safe in San Francisco. Very humid there with salt air thanks to the fog. After three years there was no rust at all. Go Rig if you're going to shoot it. If you never shoot it, use Rennaisance Wax instead.