Wonderful Engineering

Can A Stray Bullet Falling From The Sky Kill You? Here Are The Possibilities

Credits: publicbroadcasting

Celebratory firing is part of many cultures around the world, and while it is illegal in the US, many people still break the law in the heat of the moment, especially on the New Year’s Eve. So should you be scared at the prospect of a falling bullet?

Yes … well, probably … maybe … it kind of depends!

Many people have been dwelling on the question, from the U.S. military to forensic scientists and even cardio-thoracic surgeons. But most famously, Discovery Channel’s Mythbusters’ whole episode on the matter concluded that there is no straightforward answer to the question. One thing is under the agreement that if a bullet at exactly 90 degrees to the horizontal it is unlikely to kill a person upon returning to the surface. Bullets fired into the air fall back against air resistance, thus reach terminal velocities which are much lower than their muzzle velocity at the time of leaving the barrel of a firearm. Thus they are nowhere near their initial dangerous velocity.

A message by US Gov. against air shots/ Credits:massliveAs an example, firearms expert Julian Hatcher calculated the speed of falling bullets in the 1920s and concluded that his .30 caliber rounds reached terminal velocities of up to 300 feet per second (90 m/s or 204 miles per hour), while they are shot almost four times the speed. So a falling bullet fire like this will probably deliver a painful wallop or a bruise with the only chance of killing you if it hits directly the eye, ear, or mouth. Lighter bullets, like in a 9mm handgun reach terminal velocities at even lower speeds, between 150 and 250 feet per second so presenting even less of a threat.

Having said that, things can get dangerous if the shooting angles are lower than 90 degrees. Bullets fired at an angle of 45 degrees or below that can be far more lethal, since gravity is only working on the bullet’s velocity’s vertical component and not the horizontal one. So the bullet maintains its angular ballistic trajectory, doesn’t engage in tumbling motion, and thus travels at speeds much higher than a bullet shot at 90 degrees. It is also more likely to keep its initial, aerodynamically favorable orientation. Thus, they are capable of more damage.

Gun shots can travel very high up in the air depending on the muzzle velocity and weight, and the wind speed takes them in unpredictable directions, so it is likely to land very far from where it was shot. U.S. military ordnance expert, Julian Sommerville Hatcher, experimented on this phenomenon and only managed to land only 4 out of his 500 vertically fired bullets in the desired area, while the Mythbusters crew lost all their rifle shots.

Probably not! Credits: masslive

The good news is that bullets fired vertically take anything from at least 15 seconds to over a minute, so next time you hear some one going berzerk with a gun, you have enough time to rush and take cover.