JamesNoBrakes

Without doubt, war correspondents are wise to wear helmets and flak jackets while sending dispatches from shell-pounded streets crackling with gunfire.

But when Sky News reporter Alex Crawford rode into Tripoli this week on a rebel pickup truck, she was more worried about celebratory gunfire – because of the danger posed by bullets landing on her head.

While some early studies conjectured that bullets shot upwards simply vanished into space, the threat from falling ordnance is not to be dismissed.

To explore the finer details of the rule that what goes up must come down, Benjamin Robins reported in 1761 that a largebore bullet fired upwards returned to Earth three quarters of a mile away and half a minute later. More precise studies followed.

In the autumn of 1910, an RL Tippins hauled a Maxim machine gun to the tidal mud of the river Stour in Suffolk and fired two bursts of about 30 bullets straight up into the air.

With stopwatch in hand, he timed the bullets as they fell to Earth, recording flight times of about 55 seconds.

The conclusion from the experiments was that the bullets reached 2,750 metres (9,000ft), taking 19 seconds to rise and almost twice as long – 36 seconds – to fall.

Recalling the experiment, Tippins said: "We had no head cover, but trusted to the wind to carry them away far enough to miss us."

But what do we know today of the risk of injury from falling bullets?

Between 1985 and 1992, a group of physicians at the Martin Luther King/Drew medical centre in Los Angeles studied victims of gunshot wounds and identified 118 thought to have been hit by falling bullets. These included people struck by bullets while going about their everyday business, far away from known gunfire.

Only six of the regular bullets were traced by the police, to shootings that occurred up to a mile away. But some people were hit by high velocity rounds whose sources were never traced.

For those hit by falling bullets, the chance of the wound being fatal was far higher than a typical shooting. The hospital put deaths from regular shootings between 2% and 6%, while for those struck by falling bullets the death rate was close to one third.

The reason was simple – those unlucky enough to be hit by falling shells were more likely to be struck on the head, and while the bullets were travelling slower after being shot into the sky, they were still capable of smashing skulls.

According to the doctors, a spent bullet falls back to Earth with a speed of between 90 and 180 metres per second. A bullet travelling at less than 60 metres per second can cause a fatal skull injury, they added.

The hazard posed by celebratory shots led Los Angeles city council to ban the firing of bullets into the air in 1989. Later, sales of bullets in the runup to New Year's Eve were prohibited.

The issue was picked up in 2003 by the US Centres for Disease Control and Prevention, which raised alarm over the dangers of falling bullets discharged during new year celebrations in Puerto Rico in 2003/4. They logged 19 injuries, including one death, over two days.

The perils of falling bullets are not confined to war zones and inner cities. In 2008, American chef Paul Prudhomme was setting up his cooking tent on a golf range ahead of the PGA tour in New Orleans when he flinched from what he thought was a bee sting.

When he shook his shirt sleeve, a .22 calibre bullet dropped out. According to police, it could have been fired one and a half miles away. Prudhomme continued to cook with a hole in his chef's coat and a cut to his arm.

The danger of falling bullets, from celebrations linked to New Year's Eve, weddings and religious festivals, has prompted governments around the world to launch educational programmes to discourage trigger-happy partygoers.

A TV and radio campaign in Macedonia in 2005 used the slogan: "Bullets are not greeting cards – celebrate without weapons."

Spent bullets and their injuries: the result of fir... [J Trauma. 1994] - PubMed - NCBI

http://www.turkishneurosurgery.org.t...df_JTN_639.pdf

The parabolic action makes it travel away from the original point of departure, and obviously almost no one will be able to shoot exactly "straight up", but it's the downward velocity here that's the biggest issue. The 45 degree arc is what makes it able to travel such great distances.

This is a good one, discussing the size of the round a little bit, weight to diameter:

Bullets fired into the air during celebrations return at a speed fast enough to penetrate the skin and cause internal damage to other organs in the path of the migrating bullet. The bullet’s velocity required for skin penetration is between 148 and 197 feet per second. A velocity of less than 200 feet per second, which is easily obtained by a celebratory gunfire, is capable of fracturing bone and even causing intracranial penetration [4]. Spent bullets have the capability of reaching up to 600 feet per second during their downfall, and thus they have the ability to inflict damage to multiple body cavities [4]. The larger caliber bullets (ie, .45-caliber) reach a higher terminal velocity compared with the smaller caliber bullets (ie, .30-caliber), because of the proportion of their weight to their diameter [4]. Terminal velocity is difficult to calculate with falling bullets because wind resistance and updrafts can cause a spent bullet to land miles away from the initially fired site [2].

http://www.ncbi.nlm.nih.gov/pubmed/7996596

rotorhead1026

Again, the issue is whether "straight up" is lethal, and Hatcher, et. al showed that is generally isn't. The examples above relate to angled fire. I read a recent study with a bit more detail - the rounds tumble and don't pick up enough speed to be lethal - vertically. Terminal speed was 100 ft/sec plus for the heavier rounds, though - so one could be hurt very badly. Add a modest horizontal component, though (which doesn't degrade too much over the bullet's path) and you've got a real problem. People firing into the air for celebration would be launching the round from angles ranging from thirty to seventy degrees, leading to the mayhem described in post 21.

We'll agree that they're idiots. If they didn't have firearms, they'd be aiming lasers at us.

JamesNoBrakes

70 degrees is darn near "straight up" to someone firing a gun, and the rounds being fired usually ARE heavier ones (7.62), not so much .22s and the like. It's probably physically difficult to shoot exactly "straight up". That study is what, 60 years old as well? I'm seeing anywhere from 60-200+ fps from the "straight up" scenarios with fairly lightweight rounds, and there are definitely rounds that can kill in that range.

Methinks this isn't a dramatic problem due to the ODDS of getting hit, but I wouldn't tempt fate.

rotorhead1026

Seventy degrees isn't straight up, and that angle makes a difference. Try it out (mathematically)with your favorite round.

No, the study is recent, and the laws of physics haven't changed in that time. Again, the terminal velocity of a falling slug will be well under 200 ft/sec - primarily due to the fact that it'll be tumbling. If it's 200+, it probably was launched at 70 degrees or less. Now, a 200 ft/sec impact would "right smart", but I doubt any bullet would fall straight down that fast.

I Googled "terminal velocity of a falling bullet", and came up with this, too. Now these guys ain't exactly von Braun and Einstein, but the results are interesting. I'm going to try to view the show.

Annotated Mythbusters: Episode 50: Bullets Fired Up, Vodka Myths III

threeighteen

I haven't seen a classic in a while, but that looks a lot more like an SP....

DYNASTY HVY

It's a 100 percent still going strong classic which can get up and go like a raped ape and here's some info on the SP .
Boeing 747SP | Airliners.net

UAL T38 Phlyer

I thought so at first too, but it is the image posted on Youtube....they compressed it somehow to fit the screen.