I'm creating a world several hundred years after an apocalypse, but am struggling to get the decay of our current civilization right.
The world in short: Earth was hit by an apocalypse in the 2060 (nothing too fancy, just standard nuclear apocalypse with everybody throwing nukes at each other; plus some nanobots going rogue, based on that question). Several hundred years later, world is quite recovered, crowded with changed animals and demons (mutated humans). Humanity barely survived and is still scarce in the world; there are three to four bigger cities all around the world, several small villages, but apart from that not much.
My heroes are traveling through Vietnam and Siberia at some point of the story (Siberia several months or even a year later than Vietnam). Because they need to defend themselves against animals and demons, I came up with the idea to let them find weapons and ammunition stored away in a cache by the Vietcong and (in Siberia) by the Russian army in an old bunker.
My question is split in two parts:
- Can a firearm (preferably a handgun of a type used in the the Vietnam War) and ammunition stored away in a cache in the jungle of Vietnam last until about 2650 and still remain usable or relatively easy repairable? How does such a cache have to be constructed? What about a firearm (handgun and/ or rifle) + ammo stored in a Russian army bunker in Siberia?
- Can a person repair such a stored gun to fully functional conditions using only handtools that would be carried by a typical scavenger or found in the environment? This might include something like knives or a prying bar, maybe a wire cutter or an axe/ hammer, and also things found in the environment, such as sand for polishing, acid juice from fruits or animal fat. Power tools or workbenches are not allowed.
To make it clear, the weapons don't have to be in perfect condition, just restorable. Any rotten wood like a handle or stock is okay, since it can be replaced quite easily. Rust outside is also okay. Just the mechanism and the barrel have to be in such a condition they can be restored easily. Ammunition should be usable, too.
The required knowledge for our heroes is not the focus of this question, until it would be necessary to restore nearly any part inside using abilities only a gunsmith has. You can expect them to know how to field strip a gun and solve minor technical problems, since they have seen and used guns before. When they came to Siberia, their knowledge might be grown to a level necessary to understand the inner working and mechanics of an assault rifle like the AK.