Basically, this would be purchasable at the armory for a certain amount of credits.
Now there are two options:
1.Bullet belt- Extra ammo to projectile weapons
-Similar to the battery pack, only for projectile weapons.
-Would cost 100
2. Ammo Pack- Similar to the medipack, except this restores all ammo of your primary weapon, however it wouldn't be available until Stage 2 and would cost 500( Only works on projectile weapons)
The idea behind this is to allow humans to stay out in the field a little longer, and be able to make it all the way to the enemy base.