This is most notable in Battery (Back Bunker) and Snatch (Axis Ammo Site)
If you are picking up ammo for a mortar that is completely empty it will not pick up 16 rounds until you step away from the ammo crate, generally to the outside. Sometimes it works if you switch weapons a few time (Oasis). It only lets your pick up 15 rounds. This is only from ammo crates built into the map, Ammo from a field ops works fine. Not that big of a bug, just making you aware.