Is there a tutorial somewhere on how to set up ammo counters, because I haven't found any, and I have no idea how to make them.

Umm, do you mean the hud or the ammo counter on the gun?
If you mean the hud you can check out this tutorial.
http://hce.halomaps.org/index.cfm?fid=1214

The ammo counter on the gun.

Quote: ---Original message by: UnevenElefant5
For the ammo counter, here is what you do:
Make 2 planes where you want the ammo counter
find and extract this bitmap with one of the bitmap extractors on this site:
tags\weapons\assault rifle\fp\bitmaps\numbers_plate
Make 2 new materials. One names numbers0 and another named numbers1
apply numbers1 to the tens place (ex, the 6 in 60) and numbers 0 to the one's place(the 0 in 60)
I'm about 80% sure that's how it is. If it doesn't work, like the numbers count wrong ingame, flip the placement.
then modifier list -> UVW map
Go to planar, fiddle with the alignment, sorta towards the bottom, so that it lines up with your plane (your plane should be placed straight up and down)
Now you can move the planes into position on the gun model, and attach them to the rest of the gun. Re-export like normal and you should be ready to go.

Alright, that brings me to my next question:
How do you get parts of a weapon to animate (e.g. the magazine) without the whole gun moving?

Move the frame node that the object is linked to. For instance, if the magazine is rigged to frame magazine, which it normally is, then move that. If nothing moves when you move that, you're using the 3p model for a weapon, which generally has no moving parts.

Derp. Sorry, I phrased it wrong. What I meant was how could I like, say, rig a heartbeat sensor that I added to the weapon so that it flips out?

Detach it, link it to a frame sphere thingy, link the frame sphere thingy to frame gun, rig the original model to frame gun so everything moves with frame gun. Then export it and recompile.

back to the ammo counter:
How would I set up the ammo counter function in the .weapon tag?