Really? Seriously? Come on, it's common sense- Pokémon are way more resilient creatures than humans. They can survive electrocution, high-pressure blasts of water, horrible burns, poisoning, huge fiery explosions, and even just simply being rammed at high speeds by huge and powerful opponents, and the worst that will happen is that they go unconscious for a while. You think a simple gunshot wound would be enough to kill or even slightly inconvenience a Pokémon? A Bullet Punch attack has to have more force behind it than an actual bullet as far as I'm concerned, and when's the last time someone's Scizor's actually ever murdered anyone- not just KO'd them but ended their life? Yeah, that's right, never. That's the real reason why guns don't see use in the Pokémon world- just as firearms outclass swords as weapons, so Pokémon outclass firearms. You ever hear the phrase "like bringing a knife to a gunfight"? Well, now it's like bringing a gun to a Pokémon battle.