Eh, it depends. Shotguns are an Appalachia/Ozark thing - basically Eastern Seaboard - imo. Lever guns and revolvers are wild west. At least that's the popular perception of firearms.
In the forests of the Appalachian and Ozark mountains, combat is close range. Out west, lever guns and revolvers and shooting folk at longer ranges was key to victory back when you could still shoot a man in a duel and get away with it.