1) Get a 7.62x39mm ammo into your inventory.
2) Split it.
3) Observe as the original stack is showing the same amount of items as before a split.
4) Drop the original stack on the ground.
5) Observe as there is no refresh of the count of items (or where items count is read from a bad equation/function).
6) Pick the stack back to your inventory.
7) Split it again and get an infinite numbers of that type of ammo.