I thought about adding limited ammo to Thor's Hammer. But I want to keep it as simple as possible. Right now it's similar to classic weapons. No reloading, ammo/etc. So one extra item that gives the player full ammo on pickup and when you run out of ammo you can't shoot anymore. No reloading or anything.
[Edit]
Holy stuff. A box of fifty 5.7x28mm (The P90 uses these) costs over 1000$ on Impact Guns - 20$ for one cartridge. What?