I found out that it can be sort of done on live, but it is only good if you have a mauler, and your in close range. Also what you iss you hit RRYR and the second shot is your mauller, and then the person, will either be dead or be one shot. In any case the guy also said that it is not as good as the Halo 2 double shot, and it just takes as long if you shot 4 shots any way.

__________________
skadoosh