The law of guns in movies

[S&Wshooter]

Good guys have the infinite ammo cheat active, bad guys only ever carry 2 mags

James Bond never, ever carries extra ammo for anything and always runs dry when he really needs to use his gun

If the main character has a clear shot on the main antagonist, his gun will always be empty despite the fact he just fired 300+ rounds from a revolver

No matter how skilled a fighter the protagonists mentor is, he will be killed by 2-3 street punks

(if you want to see a few examples of this, watch "I'm Gonna Get You Sucka")