Gatling guns may be fast and powerful, but they move slow. True, if you had a gang with, let's say, 5 members, all wielding gatling guns, or even duals, it'd be impossible to get past a single door. But no one's to say that the stats have to be realistic. I think the players can agree that a gatling gun that shoots 1 or 2 bullets per second, and freezes, and has crappy strafe is still good enough, right?