There are, indeed and surprisingly, numerous instances of "good guy with a gun" managing to deal with "bad guy with a gun" or "bad guy threatening to cause grievous bodily harm to innocents".
Mike mentioned the events that took place in churches, but we can also remember Elisjsha (why didn't his parents put more "s" in his name...?!) Dicken. Who, incidentally, gave birth to the Dicken drill (10 rounds, 40 yards).