Hollywood depictions of firearm victims being thrown through plate-glass windows are inaccurate. Were this the case, the shooter would also be thrown backwards, experiencing an even greater change in momentum in the opposite direction. Gunshot victims frequently fall or collapse when shot; this is less a result of the momentum of the bullet pushing them over, but is primarily caused by physical damage or psychological effects, perhaps combined with being off balance. This is not the case if the victim is hit by heavier projectiles such as 20 mm cannon shell, where the momentum effects can be enormous; this is why very few such weapons can be fired without being mounted on a weapons platform or involve a recoilless system (e.g. a recoilless rifle).