A minigun is realistic by any means in fall out, and they are not hard to come by especially if your a mutant because mutants are prone to carry huge weapons such as that. However the laser minigun is the weapon id consider unrealistic seeming only certain factions used it and its power is unparallelled to most gun. The gun I am carrying is not the most powerful of miniguns in Fall out which is why I chose it.

It can tear you a new ass if your on the wrong end of it of course, but considering it chews up ammo like a beast, he would have to use it sparingly plus as I said in the post it is for last resorts not for every situation that the group may encounter.