Bullets falling back to earth

THe San Fernando valley near L.A. always has some also - just a ways away.

Martin

Reply to
Eastburn
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You don't measure bullet speed in miles per hour. But you are pretty close to the maximum terminal velocity. 1mph =

1.467 fps so 180 mph = 264 fps. The army found that the maximum terminal velocity of rifle bullets was about 300 mph. For comparison think of a baseball at 80 mph. If the baseball weighs about 2.5 times the bullet, then the energy would be the same as a bullet at 300 fps. Of course a baseball weight many time the average rifle bullet. Or, for another comparison, many air pistols max at about 300 fps. So let's not get carried away with the possible damage of a falling bullet.
Reply to
George E. Cawthon

Tim -

Have you ever seen a softball sized hail that falls - smashes roofs to junk and puts deep bends in cars.

Then there is the smaller stuff that are golf ball size that knocks out people left and right.

I suspect you are talking about pea size or rice size. Yea - that is almost like snow.

Martin

Reply to
Eastburn

lane, If you can post a link to that article about the KKK member killed by the bullet I would like to read it. Dennis

Reply to
Gunluvver2

I think you will find that softball size and probably golf ball size hail often has much more energy than the terminal velocity of a falling rifle bullet. By the way, nobody mentioned pistol bullets. Although they often weight more than rifle bullets, pistol are much less aerodynamic than rifle bullets and would not achieve as high a terminal velocity and would cause less damage than a pointed rifle bullet.

Reply to
George E. Cawthon

There just seems to be the AP story: http://209.157.64.200/focus/f-news/1028558/posts

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Sounds "suspicious" to me- bullet went right through his skull. Wanna bet that the guy with the gun turns out to have actually been up in the tree, or something like that.

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Shannon's Law has resulted in $500K worth of electronic sensors being installed on telephone poles in an area where there is a lot of gunfire..

Best regards, Spehro Pefhany

Reply to
Spehro Pefhany

here in New Orleans it was getting to be a ritual of people firing guns to celebrate the New Years.... well with this one girl was killed by a falling bullet... another had a bullet in the head(thougth someon hit her in the head with a bottle on Bourbon St. when she got to the hospital the doctors found a bullet lodged in her head.. and several other incidents... these idiots who were firing the guns never thought much of where the bullets would fall..... In Iraqu it is common to celebrate by firing guns... remember Saddam when on tv and giving a speech to his people,, he took out a 45 auto. and stood in front of them and emptied a clip out over their heads.... when in desert storm and desert shield the friendly troups passing the american soldiers in trucks and tanks, to salute them they would fire their rifles in the air....

Reply to
jim

"Gunluvver2" wrote in message news: snipped-for-privacy@mb-m29.aol.com...

I don't understand how anyone can think that falling bullet doesn't have the capacity to inflict a fatal injury. There are so many reports, they cannot be ignored. It is an urban myth that they are not dangerous.

Besides the ones that Spehro already gave you:

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"20 Kuwaitis died from falling bullets"
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"cousin of mine was killed several years ago during Mardi Gras when a falling spent bullet pierced her brain"
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"the .45- caliber bullet struck Stephanie just below the knee and 6 to 8 inches down her leg before stopping near her ankle."
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The bullet left a small burn mark above her ankle before it entered just below the ankle and traveled about four inches into her foot
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there was a hard lump in the right side of her neck. She'd been hit by a falling bullet
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Terry Smith lives with a bullet lodged in her left lung & death of a 14-year-old Shannon Smith in June 1999
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He had been hit in the head by a falling bullet last week
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Research indicates that a bullet fired into the sky can climb and remain in flight for 30 seconds or longer. As the bullet falls, it can hit a ground level velocity of approximately 140 miles per hour; a velocity which can penetrate the human skull.
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a falling bullet instantly felled Joe. It entered the back of his skull at the top of his occipital lobe, penetrated through his cerebellum, and lodged just millimeters from Joe's spinal cord. Had the bullet traveled one half-inch further, Joe would have been killed.
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Reply to
lane

Sigh..much LOWER velocity then they went up with. Around 300 fps +/- impact velocitiy on average. The AK-47 fires its 7.62mm, 125gr bullet around 2300feet per second. The AK-74, uses a 5.45mm bullet with a weight of around 55grs and a muzzle velocity of around 2900 FPS. Of course the heavier bullet will retain far more kinetic energy than the small one.

Terminal velocity is dependant on shape of the leading profile. If a bullet was fired STRAIGHT UP, it will generally fall and land on its base. While the bullets upwards trajectory slows, then stalls, then reverses, its STILL spinning as a result of the rifling in the barrel of the weapon it was fired from. This was demonstrated many times by various ballistics labs.

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in the Sky

We frequently get questions about firing bullets vertically into the air. The most frequent question is, "Will bullets fired into the air return to the earth at the same speed they left the gun?" Other questions asked are; "How far does the bullet travel when fired vertically and how long does it take to come down, or does the falling bullet have enough energy to be lethal should it strike someone on the ground?"

Some have tried vertical shooting, but very few have had any luck hearing the bullet come back and strike the ground. When a bullet is fired vertically it immediately begins to slow down because of the effects of gravity and air drag on the bullet. The bullet deceleration continues until at some point the bullet momentarily stops and then it begins to fall back toward earth. A well-balanced bullet will fall base first. Depending on bullet design, some bullets may tumble on their way down and others may turn over and come down point first.

The bullet speed will increase until it reaches its terminal velocity. The bullet reaches terminal velocity when the air drag equals the pull of gravity or stating it another way, the bullet weight and drag are balanced. Once this velocity is achieved the bullet will fall no faster.

In 1920 the U.S. Army Ordnance conducted a series of experiments to try and determine the velocity of falling bullets. The tests were performed from a platform in the middle of a lake near Miami, Florida. The platform was ten feet square and a thin sheet of armor plate was placed over the men firing the gun. The gun was held in a fixture that would allow the gun to be adjusted to bring the shots close to the platform. It was surmised that the sound of the falling bullets could be heard when they hit the water or the platform. They fired .30 caliber, 150 gr., Spitzer point bullets, at a velocity of 2,700 f.p.s. Using the bullet ballistic coefficient and elapsed time from firing until the bullet struck the water, they calculated that the bullet traveled 9,000 feet in 18 seconds and fell to earth in 31 seconds for a total time of 49 seconds.

As a comparison, the .30 caliber bullet fired in a vacuum at 2,700 f.p.s. would rise nearly 21.5 miles and require 84 seconds to make the ascent and another 84 seconds to make its descent. It would return with the same velocity that it left the gun. This gives you some idea of what air resistance or drag does to a bullet in flight.

Wind can have a dramatic effect on where a vertically fired bullet lands. A 5 mile per hour wind will displace the 150 gr. bullet about

365 ft based on the time it takes the bullet to make the round trip to earth. In addition the wind at ground level may be blowing in an entirely different direction than it is at 9,000 feet. It is no wonder that it is so difficult to determine where a falling bullet will land.

Out of the more than 500 shots fired from the test platform only 4 falling bullets struck the platform and one fell in the boat near the platform. One of the bullets striking the platform left a 1/16 inch deep mark in the soft pine board. The bullet struck base first.

Based on the results of these tests it was concluded that the bullet return velocity was about 300 f.p.s. For the 150 gr. bullet this corresponds to an energy of 30 foot pounds. Earlier the Army had determined that, on the average, it required 60 foot pounds of energy to produce a disabling wound. Based on this information, a falling 150 gr. service bullet would not be lethal, although it could produce a serious wound.

Many other experiments have been made to find the amount of air drag on a .30 caliber bullet at various velocities and it was found that the drag at 320 f.p.s. balances the weight of the .021 lb. (150 gr.) bullet and terminal velocity is achieved. For larger calibers the bullet terminal velocity is higher since the bullet weight is greater in relation to the diameter. Major Julian Hatcher in his book Hatcher?s Notebook estimates that a 12 inch shell weighing 1000 pounds and fired straight up would return with a speed of 1,300 to 1,400 feet per second and over 28 million foot pounds of striking energy."

********************

Its been my experience that most fatalities or injuries from "spent" bullets were the result of a bullet that was fired at a low angle (less than 45', and as such retains a good percentage of its forewards velocity as gravity drags its trajectory downwards. Some of those folks are not particularly careful when doing the AK Dance, as witnessed on TV broadcasts over the last 20 yrs from the Middle East.

Gunner " ..The world has gone crazy. Guess I'm showing my age... I think it dates from when we started looking at virtues as funny. It's embarrassing to speak of honor, integrity, bravery, patriotism, 'doing the right thing', charity, fairness. You have Seinfeld making cowardice an acceptable choice; our politicians changing positions of honor with every poll; we laugh at servicemen and patriotic fervor; we accept corruption in our police and bias in our judges; we kill our children, and wonder why they have no respect for Life. We deny children their childhood and innocence- and then we denigrate being a Man, as opposed to a 'person'. We *assume* that anyone with a weapon will use it against his fellowman- if only he has the chance. Nah; in our agitation to keep the State out of the church business, we've destroyed our value system and replaced it with *nothing*. Turns my stomach- " Chas , rec.knives

Reply to
Gunner

General Julian Hatcher did *extensive* experimentation on this very topic and wrote about it in "Hatcher's Notebook" (required reading in some circles).

An interesting tidbit, it's almost impossible for the shooter to land bullets near the firing position. Even with mounted weapons; the winds aloft, especially during the last second of upward and first second of downward travel when the bullet travels up 16 feet and down 16 feet at an elevation of approximately 9000 feet, really can push a bullet around.

Anyway, it's an interesting study, documented in book that is quite a good read with plenty of metal (eg. heat treatment) content.

Highly recommended!

Reply to
Doug Smith

Climbing around on the cross mabye?

Jim

================================================== please reply to: JRR(zero) at yktvmv (dot) vnet (dot) ibm (dot) com ==================================================

Reply to
jim rozen

No correction. You're 100% right.

I've long since forgotten what the exact number for "terminal velocity" is (120-ish MPH, isn't it?) but whatever the value is, that's the top speed Mr. Bullet is going to attain on the way down. Even so, there

*ARE* fatalities from bullets fired skyward, even here in the good ol' US of A. The last one that happened close enough to me to make the local rag (and therefore be able to hit my own personal "radar screen") was a 2 year old in Detroit on a new years eve a few years back. Id memory serves me correctly, the round came in a few degrees off the vertical, broke her nursery room window, continued into her crib, which was located just below the window, and hit her in the head.

Idiots forget that "what goes up, must come down".

Reply to
Don Bruder

I have plenty of holes in the thin gauge corrugated aluminum sheets that make up the roof of the canopy at the back of the shop. Some of the holes make it appear that the bullet hit it flat on the side. None of the holes look like a hole would if the bullet had been shot at it. None of the falling bullets have ever pierced the thicker gauge steel roof of the Morton building the canopy is up against. I've never inspected the builtup roof of the main building to look for damage from falling bullets. I do have a bullet hole in the rollup door in the front of the building. That hole was not from a falling bullet.

It tends to sound like a war zone in East Los Angeles on July 4 and New Years. The police usually park under an overpass or other structure at midnight on New Years Eve.

Les

Reply to
Ljwebb11

Tim: Check "Hatcher's Notebook" and in the section on 'Bullets from the sky' he records considerable data on experiments of vertical firing of .30 cal 150 grain ammunition. With a muzzle velocity of 2700 ft/sec they averaged only 300 ft/sec when they returned to the ground. This gives an energy level of 30 ft. pounds and the Army considers 60 foot pounds to produce a disabling wound. ("Hatcher's Notebook", Third edition, pages 510 to 517). The majority of the bullets returned to earth base first.

J.R. Williams

Reply to
J.R. Williams

info.

Terminal velocity is a function of weight and aerodynamics. A led bullet will have a higher terminal velocity than a feather. The terminal velocity is reached when the aerodynamic drag of the object equals the weight of the object.

Pete.

Reply to
Peter Reilley

I don't know for sure BUT I would think that terminal velocity would depend on the drag coeficient and that can vary all over the place for different shapes or even orientiations of the same object. ...lew...

Reply to
Lewis Hartswick

It is unclear if the accounts given below involve bullets falling only under the influence of gravity - that is straight down. It is far more likely they involve "stray" bullets that retain some component of forward velocity imparted by the firing charge. Gunner's comments, elsewhere in this post, make it clear that "service size" projectiles falling only under the force of gravity are not likely to inflict mortal wounds.

Kinetic energy = 1/2 mv*2

In the case of a 150 grain bullet falling at 300 fps, its kinetic energy is:

Ke = 0.5 x (150/7000)/32) x 300*2 = ~30 ft. lbs.

Bullet weight in grains divided by 7000 = weight in lbs. Weight divided by

32 = poundals or mass associated with gravity.

Bob Swinney

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Reply to
Bob Swinney

Tim, consider this:

Fire a cannon ball exactly horizontal (level) with the earth. At the exact instant the cannon ball leaves the muzzle, drop another cannon ball from the same height. The 2 cannon balls will reach the earth at the same time.

Reply to
Bob Swinney

When we reshingled the roof, we found a .45 slug stuck in the ridge row point first. It had penetrated 3 or 4 layers of fiberglass shingles before stopping. Stupid neighbor.

The nose shows spiral scratches from the grit on the shingles. I still have it in a box somewhere...

StaticsJason

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Reply to
Statics

That's for people with their arms out. Over 200mph for people with their arms folded back.

Bullets are aerodynamic, but only when pointed forwards. They're also only barely stable (excess stability requires drag), so they're unlikely to re-orient themselves correctly after first starting to tumble. Some figures claim around 400mph for an oriented rifle bullet, but a mere 150mph for one that's tumbling.

It is possible to go supersonic in free-fall - the WW2 Grand Slam bomb was designed to do just that (and caused a lot of aerodynamic headaches for trying to).

As casualties have already been reported from the celebratory firing, the question is a little academic.

Reply to
Andy Dingley

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