Firestorm ammo bug

The same thing happened to me. Specifically, it occurs for the MG and rifle ammo, but it may happen to others periodically, though I haven't encountered others yet.

You can see from the image below that next to my crosshairs, it says that ammo is full. But in my inventory on the bottom right, it shows completely empty.

You can only carry 4 different kinds of ammo. So if you have shotgun shells and no shotgun ect drop then to make room 👍

@Shakermak3r Do you know if this is the case for only the small backpack? So, if you have the medium or largest backpack, you can carry more types of ammo?

Not to sure mate

Well I just checked with the medium backpack and it still limits your ammo type carry capacity to 4.

Hmmmmm.... if my four different ammo types aren't full capacity, then I can carry more ammo types. So, if I have an MG, rifle, sniper, and pistol ammo, and I only have say 1 extra round of MG, I can carry a fifth type of ammo. So, I think that it's all about percentage ammo full. You seem to be allowed 400% in total ammo capacity, no matter the combination of ammo types. At least from what I can tell so far. 

@SterlingARCH3RAgreed. You can carry different types of ammo (more than 3) - depends on total weight.

Yep, happens to me about once every three games or so. The last time though all I did was change from full auto to semi auto a couple of times and then all my ammo disappeared. Couldn’t pick up any more either which made all the MGs useless for the rest of the game.