Do a search for "Billy Dixon" and "Adobe Walls". A group of buffalo hunters had to deal with a group of hostile (IIRC) Kiowa or Cheyenne. From a refuge in an old adobe tumble-down, Dixon shot either the chief or the medicine man at over 1,200 yards. His rifle was similar to the Quigley gun. (There's argument whether he was shooting at one and hit the other, but that's sorta beside the point. One shot, one kill, end of problem.)
Art