That thing where all your clips other than the last one, are full. Now I've no doubt that it's impossible for us to keep track of which unit has this many clips, with this many bolts in them, but good news! You're in the heat of battle, you don't have time to hold on to that half used clip! You toss it, or you spend six seconds exposed with your hand off your weapon, shoving it into a pocket you don't have.
But is it possible to come up with a small Lua. file that deducts the ammo you have left in the cilp you take out from your gun, from the overall ammo count?
It's really, really "gamey" and has utterly no place in a FPS, let alone in a mod for "REALZIM HURRDY HUR".
Thank you for your assistance.