I have a similar problem I'm trying to work through:
I'm going to need to put my firearms and ammo in a long-term storage locker for approximately 1 year. My firearms will be stored inside a safe, my ammo in individual sealed ammo cans. The storage site is located in KC area, so it will be subject to pretty significant fluxuations in temperature and humidity.
Some ideas I have for the firearms:
1. Using a zerust protection module in the safe
2. X2 750 gram silica dry packs
3. Wipe down guns with oil
4. Seal the safe with tape to reduce humidity buildup
For ammo:
1. All ammo stored / sealed in seperate ammo cases
2. Silica dry packs in each ammo box
Note: I do not have access to any electrical outlets in this storage unit, so I have to deal with the humidity with a non-electrical solution.
One concern I have with storing guns wet is sometimes the lubricant on the weapon can react to the case the gun is stored in. I don't want to risk marking up the finish.
Any suggestions are appreciated.