There is one way to get this to work... but only if there is a way to access inventory during combat. Anyone know of a mod to do that? Maybe you could use it with reckoning.
Anyway, when you're in town, and you have a bandolier that says zero in the bottom right corner, and no ammo boxes in your inventory, what you do is hit your inventory, unequip the bandolier, then re-equip it. then when you exit your inventory, you'll see you have like 50 rounds (or whatever quantity your bandolier holds) in the bottom right corner. There's got to be some way to access inventory during combat... this would be a great quick fix