The ammo boxes contain invisible ammo packs inside.
If you take some packs, they will refill and are visible for about 1 sec and become invisible again.
Ammo box:
After taking 2 packs:
1 sec later:
The ammo boxes contain invisible ammo packs inside.
If you take some packs, they will refill and are visible for about 1 sec and become invisible again.
Ammo box:
After taking 2 packs:
1 sec later: