Maybe not an ammo count, just a mag count. I think the ammo count could be way ocercomllocated unless you hacked the game and xbox to transfer certain info via USB to a chip in the controller. Or with the original idea, maybe instead of a segmented display, you cound use LEDs , eg 3 green, 1 orange, 1 red, , full ammo all LEDs, low orange, none/very few red.