To do this trick, u must enable the "flcl" code. Then go to experiment. Then keep on fighting people until you gat an m16 or an automatic gun. Simply hide the automatic gun or m16 and grab another gun (not the m16 or automatic gun). When that's finished, get back to your m16 or automatic gun. Then shoot. When you shoot, IMMEADIATLY switch weapons. You should shoot and switch weapons at the same time. Instead of the m16 or the automatic gun shooting, the other gun that you had shoots three bullets. I tried this cheat and it would work. Trust me.