bullet audio/visual-effect only
tested only on 2nd lvl of no mercy on single player with shotgun and 1 pistol so may work on other places
get a pump shotgun and one pistol(not double) and start switching between them rlly fast,if u start pressing the fire button it will sound and look like u fired a bullet but the bullet will be unable to do damage.if u have any question contact my gamertag on xbox-burningfin.or e-mail me a fishhappines@aol.com