[RUNGSI]

the ammo.urc file is calling to the name in your weapons .tik file
Just edit this line in your weapons .tik file:
classname Weapon
weapontype mg
name "BAR" <--- right there

just change that to your weapons name and then include your new weapons hud_ammo_.urc file

example for a M3A1 greasegun
m3a1.tik file:
classname Weapon
weapontype smg
name "M3A1"

then make a .urc file named
hud_ammo_m3a1.urc
and edit the toplinein the urc
menu "hud_ammo_M3A1"