If the refinement of the idea above gets accepted:
1) As much as it would be desired, boxes should be unmoddable, or moddable only once, preferably requiring WK and only with bulk mods (330+ ammo maybe is just a little too much, but 580+ is waaaaaaay too much for such a device, and i don't even want to think what is supposed to happen if some smartass slaps a Nano on it).
2) Reloading the "box" and reloading the weapon should be separated. There is no wrong with having to do "z, r, z" when you're outside combat to prepare for the next one, especially if it helps you reload as if you had an extra level in Reloader (just about enough to be balanced, though i'm not quite sure it won't break something given the right conditions).