Gun maintenance includes removing rust that has set in during storage or lack of regular lubrication. The main concern of rust removal is to retain the gun’s bluing. Regular oiling of the gun will prevent rust from setting in, but once established, rust must be removed with care and patience. The materials needed to safely remove rust are readily available and the procedure is straight-forward.
Unload the gun. Remove the magazine if it has one and check the chamber to ensure that it is empty.
Cover your work area with old newspapers. You will be using oil to work on your gun and it will go everywhere. Have rags handy for cleaning up.
Swab the rusted area on your gun with gun oil. In a pinch, regular household oil or even vegetable oil will work. Rub the area with a cloth and remove as much rust as possible. Continue to swab the area with oil and rub it with the cloth until no additional rust can be removed.
Apply more oil and rub it with number 0000 steel wool to remove any remaining rust. Do this carefully to prevent rubbing off the gun’s bluing.
Wipe the oil off the treated area to remove any rust particles that were trapped. If rust remains on the gun, reapply oil and continue to rub the area with the steel wool. Repeat the process until the rust is gone. Finish the process by lubricating the entire gun.
Use a wire wheel carefully to grind out any areas of deep rust that can't be removed with steel wool. This procedure will remove the gun’s bluing, which you must replace immediately to protect the metal. Finish the process by lubricating the entire gun.
Once rust has invaded your gun it will likely reappear in the same spot, even after you’ve removed it. Inspect the affected area often and repeat the de-rusting procedure as needed. You can prevent recurring rust by covering the gun often with gun oil.
If aggressive rust removal requires that you re-blue the treated area note that antique guns will blue satisfactorily with over-the-counter bluing kits. You’ll be able to do it yourself and finish the process from beginning to end. Newer guns with higher amounts of alloys in their metal compositions, however, will blue unevenly and may discolor the gun’s finish when re-blued with these kits. You’re better off having a newer gun re-blued professionally to retain its appearance.