Is there a way to make them ONLY use one gun? Right now I choose their favorite and they use others.
Favorite means that its the weapon a bot uses most of the time, but not every time.
HOWEVER, some weapons such as the Barrett have been modified so that if set to Favorite Weapon, the bot will use it all the time.
Only a few always respawn with one weapon; Barret, maybe the Minigun (I don't remember), Knife, Chainsaw, and LAW. Those weapons have some sort of hard-coded, unchangeable attribute that forces bots with them as their Favorite_Weapon to always use them no matter what.