This creates the foundation of turret ammo through the "turret use ammo" subsystem flag. Turret ammo works in the same manner as ship ammo, where the ammo is equal to bank capacity divided by the cargo size of the weapon. This was tested using the Blue Planet: War in Heaven mod.
Test case: UEFg Narayana turrets 19 through 21, all of which contain Apocalypse torpedos with a $Cargo Size: of 2.5, were changed to use ammo with a $SBank Capacity of 20, resulting in a total ammo capacity of 8 torpedos. The Narayana was ordered to attack a GTCv Diomedes; it fired 8 torpedos each from turrets 19 through 21 before stopping. The mission was left to proceed for an additional 2 minutes, in which time the Narayana did not fire any more torpedos. Note: The Apocalypse takes 20 seconds to fire each 4 torpedo burst.
Conclusion: Success