I added a few nodes, so that you can never pick up more than Max Ammo, which I have set to 60.
Ammo Pickup is set to 30.
So I can only pick up ammo if Current Ammo is less than 60, aka 59.
If Current Ammo is equal to Max Ammo (60) , then the ammo pickup will not destroy.
Also added that Ammo Count does not exceed Max Ammo (60)
It adds a little bit of tactical management for the player, where you can choose to pick up ammo if you have a Current Ammo of 48, and thus you get plus 12 ammo (Max 60) and wasting 18 ammo.
Or you wait until your Current Ammo goes to 30 or lower, and then pick up ammo, thus you get plus 30 ammo.