(SWEPS) Can you have ANYTHING as your SWEP.x.Ammo?

Simple as the title says. Can you have ANYTHING you like as your ammo type? Or must it use a pre-defined set of ammo.

I’m not concerned about functionality with any ammo entities, I’m just concerned that I’m sharing ammo between SWEPS and they are heaps different and my autism does not like it.

http://wiki.garrysmod.com/page/game/AddAmmoType + Predefined ones.

And I assume I just chuck a LUA file containing all this stuff in autoexec?