Ah, in that case, i dont think you can do what you want. I'm not familiar with the sheet, but I can see it is set up to change one single value, and its hardcoded in. If your GM is a pro user and has installed the ammo script, you could extract the full macro and tweak it to do what you need. To do that, make an attack roll, then click your mouse in the chat bar, click the up arrow, and you should get the full attack. Copy that and paste it here and we can try to tweak it. That said, there might be a simpler solution. Dont track Bullets in your pistol, just track Loaded Rounds. Then each time you load it, manually reduce your Bullets by the guns loaded size. It's still manual, but you dont have to do it as often - once per reload.
