Coat with a lubricant and wrap in Saran Wrap. Interestingly enough, the initial use of Saran Wrap was to prevent rust on guns shipped overseas during WW II. The air/moisture barrier strength of Saran Wrap is outstanding.
Make sure that you get the "original" Saran Wrap and not any of the "cling" wraps. Saran wrap is made of a distinct resin, versus most wraps which are polyethylene. From a barrier protection standpoint, Saran Wrap is a safe door and other wraps are a screen door.
BTW, I used to work for Dow, but no longer......Saran is the best stuff out there for air/moisture protection.