David,
One basic Armament Subsystem was the M21 Armament Subsystem (1964-1975).
M21 Armament Subsystem (1964-1975). The UH-1B/UH-1C/UH-1M "Huey" could be armed with twin side mounting 7.62mm "miniguns" and two XM157 or two M158/M158A1 seven-tube 2.75 inch rocket launchers on the Emerson M21 armament subsystem. The M21 was an up-gunned M16 which used M134 "miniguns" in place of quad M60C machine guns. The M134 used a MAU-56/A delinking feeder. The pilot used a XM60 reflex-type sight for both guns and rockets. The copilot used a flexible reflex sight which depressed or flexed the "miniguns" only. The M21 was type classified Standard A (over 406 units were built).
XM21 armament subsystem with XM157 launcher (with M6 quad M60C machine gun mount)
In the game, you find that the UH-1B gunship has 2x M60s and 2x 19pods FFARs (9 ammo x 2 FFARs), instead of 4x M60s and 2 x 7pods FFARs. On a closer look you will understand that the equilibrium is the same, one rocket pod in the place of 1 M60 gun.
cheers,
Pyros