So I picked up strong and decided to give him a better mini gun. I took the one he had and scrapped it. Now the mini gun uses ammo. Screwed up huh? Wish I would have known...

Yeah default NPC weapons don't use ammo, though didn't think you could have removed his default gun. Think only for settlers can you modify their defaults.

Well, you could just give him a melee weapon now. A super sledge would work nicely.