Quoted By:
Realistically, Pokemon would BE the guns.
If a Pokemon can stop a high-speed bullet with its hide, why not fire another Pokemon at it? Chop up claws and horns and make them into effective piercing rounds, carve internal organs and make batteries out of electric and fire innards, augment firing mechanisms as well as power with psychic bullshit. Pokemon are ultimately just another resource—coincidentally the perfect one for subduing other Pokemon.