Right now I have three script files set up. They are named "infammo_enable.cfg", "infammo_disable.cfg", and "infammo_shoot.cfg" for ease of sorting. In my "settings.cfg" I have bound Kpad8 to exec the enable script and Kpad9 to exec the disable script.
The enable script contains:
bind mouse1 exec infammo_shoot.cfg
That script then contains:
gamefunc_fire give ammo
Then the disable script contains:
unbind mouse1
The resulting effect is that every time mouse1 is held, it constantly execs the shoot script and it fires and then adds full ammo. Unbinding mouse1 thankfully only unbinds it from the key-related binds and MouseButton0 (left mouse) still remains as Fire to the game under the "eduke32.cfg", so I can still shoot even after unbinding.