have you put the plugins in the plugins directory??
i find this much easier with HHT not HMT, i had the same problem, the weapon fires nothing, but then i used HHT(halo hacker tools) and it worked to perfection,
if you download HHT(no plugins required):
scroll down to [weap] tags,
find your weapon and click it
look to the box on the right
were it says 'dependency swapper' on top of that box click the arrow next to it pointing right,
a new box will appear named tag editor
scroll down to 'projectile'
drop down box
selct the number, usually
0
third from the drop down box 'ammo per shot' make ammo per shot,
0
Ranger