When it comes to long-term preservation of firearms (and most other metallic items), items such as Cosmoline and RIG (Rust Inhibiting Grease) were the long-accepted solutions, particularly with military firearms. As I understand it, Cosmoline and RIG are no longer manufactured, and as it is, the military has gone to vapor-barrier bags which are much quicker and easier.
A question to the chemists from a non-chemist: Would any grease be acceptable for firearms preservation? I.e., preserve without resulting in any long-term deterioration/softening of wood and offer sufficient protection to metal? I'm sure that someting like Mobil 1 Synthetic Grease is superior to RIG in the area of lubrication, but why would RIG be better at preservation (if indeed it is)?