However, the Golden Age Past did leave us two things: enough gasoline,
enough bullets.You're not taking their stuff, you're activating their stuff's downside. Relevant tags are :
Autofire (mechanical, cue, constraint): at the character’s option,
the weapon makes an area attack (cf), but must imediately
reload (cf).
Reload (constraint): using it means the character has to take
specific action to reload or reset it before she can use it again.
If their gun has [autofire], they decide if they use it or not. They manage their ammo by themselves. They should know.
If the gun has [reload], they should know that sooner or later they'll have to reload and
of course that'll be at the worst moment ever, 'cause that's how a shotout play in popular fiction.
I find counting bullets difficult because of how AW violence works. You're not counting by 5-seconds increments or doing discrete actions like "I fire three bullets at that guy".
In my games, a player seizing by force usually looks like "fuck it! I'll draw my big-ass magnum and go for the child, bam bam bam! I'll down everyone of them motherfuckers if I have to!" How much bullet did they fire? 4? 9? Who know ? A lot ! All I know is that I'm making a little note in my head : "mmh, don't forget to activate their gun's reload tag."
Remember, always choose a move that follows from the fiction. You're not gonna activate the gun's downside if he didn't fire a single shot ! That's not what honnesty demands. But they have a beretta and pulled the trigger like crazy ? Hell yeah go make that move. Make is as hard as you like ! Like "Okay Keeler, roll +hard to seize by force (miss) ooh boy. You rise from your hide both guns blazing but when you open fire all you ear is "click click click". Seems to me you weren't conservative enough with your ammo. Wasn't it your last clip ? You can feel their barrels looking straight at you. What d'you do ?"
You
can, of course, make a custom move to manage that, and make it as minute as you want. There's even one in the rulebook, p. 270.
After you go into battle with your vehicles, guns, and gear,
roll+sharp. On a 10+, you conserved your resources. Good job.
On a 7–9, choose 1:
• You’re running dangerously low on fuel
• You’re running dangerously low on ammo
• Your gear needs maintenance and repair
On a miss, the MC makes a hard move as usual (or says it’s all
three, or says you’re flat out of one thing).
But even this is abstract.
Dunno, counting bullets looks like a hassle to me, and I don't see where the fun is, neither for me the MC nor the players. But if that's how you and your players roll, custom-move the shit out of it ! Like :
Cue lots of "Well, if I'd known I was low on ammunition then I'd have..."
Make them a custom PC move that says something like, dunno,
"Trigger discipline :when you enter a battle, roll +sharp. On a 10+, if your guns have the [reload] tag, treat them as if the don't. On a 7-9 hold 1 : you can spend this hold whenever the MC goes "your gun's empty" to fire one last shot. On a 6- nothing special except your enemies know you're such a gun nut and might (will) take you as their prime target." or something.