The main struggle with keeping ammo clean and usable for long term storage is that it remains in a cool, dry place. While dry boxes and desiccant are a go-to, you can also vac pack rounds.
Yes, there are mushrooms, have you see all this rain?
It’s cheap (you can buy a sealer and a huge stack of bags for under $100) and gives you the option of making small packages (the picture has 80 rounds of good ol’ Russky wolf booty) that you can leave at the camp or with your truck gun. Plus you can squirrel it away anywhere you want such as in the dirt of the cactus on your porch, under the aquarium rocks, whatever, I don’t judge. These packs as set up are the size of a paperback book.
Some argue the vac process will take the moisture out of the propellant or primer, but I personally have tested a whole 500 round case of .223 that I had stored like this for 12 years and didn’t have a single hangfire, misfire or squib.
I talk more about how much ammo is enough ( I like to make furniture out of it) and some ideas for storage here in an article over at Tac.44.com.
