Wouldn't be as easy as you think. If you have to go find the zombie's body(ies) you just launched with the thundergun, and sit there for 3 seconds holding X, it is still very possible to get trapped.

I know / heard that there used to be this machine that gave you max ammo everytime you bought it, but was taken out for being overpowered. So what I'm thinking can happen is this:

There would be a question mark outlined on the wall somewhere (preferably a hard to get/risky place to get (as in risky to head to during the middle of a round)) that you could purchase ammo for your box weapons at 1,500 points (6,000 for upgraded weapons)

Idk, just an idea. Anyone agree/have any changes you could make to further balance it?

Edit: Maybe the question mark can randomly move just like the box, and when it moves, it doesn't give you the ammo you purchased and doesn't give you a refund (or maybe it should? no idea on this one)

That would be a cool perk.

(using the same name as the old ammo perk)

Ammo-matic (or something like that):
Cost: 3,000
What it does: It acts like the scavenger in the sense that you can pick up ammo from dead zombie bodies. You get one clip of ammo per zombie. This might sound overpowered, but during a horde of zombies, running over dead zombies looking for ammo could be risky. Also, the ammo drop only lasts as long as the dead body's sprite (graphic) is there. If the round ends (the last zombie is killed), the ammo drops also disappear. Also, when receiving full ammo power-up, the player also gets their loaded clip full (not having to reload before getting max ammo).

Idk, it seems a bit overpowered to me, but I couldn't find a way to balance it any better.

Edit: I should also state that this would only go into future zombie map(s), and not patched into older ones (this hasn't been done anyways, but stated for clearance)