Wild West Tech

[Cyrille]

 I have been watching a T.V. show named "Wild West Tech. "  This series deals with various inventions made in the 19th century dealing mostly with firearm inovations and/or improvements. For the most part I agree with what is shown, I'm not that technically educated or minded for that matter. Anyways I have heard it stated that a.45 Colt bullet could take a man's arm off at 15 or 20 ft. I believe that it will substanally damage the arm, possibly making it forever useless, provided the shot victim survives. But to actually sever it from the torso, I believe would be a very rare thing.

Another thing I've heard, on a diffrent show is that a person hit by a bullet doesn't fly forward, backward or sideways depending on where the impact hits them. Any thoghts on these subjects?

[Frenchie]

No way any .45 will blow a man's arm off, not enough kinetic energy to do that.

Which way someone falls when hit depends on which way they're moving, their balance, and the reaction of the central nervous system to the shock of impact and penetration. Sometimes they don't fall at first. I talked with a Korean War vet who said he shot two men with an M1911, one charging toward him and one standing still, and they both fell forward.

Here's something interesting I found on http://civic.bev.net/shawnee/index.html

The information following is especially important to round ball shooters, as it has recently been proposed, in some circles, that saboted pistol bullets and/or bullets of similar design, intended for use in the in-line firearms found today, are the only responsible or lethal projectiles for hunting.

If you ever wondered how all those critters/bad guys/soldiers died the first 300 years of firearms history, here might well be your answer...

A Temporary Digression While I Ride One Of My Hobby Horses:
or,
A Short Disquisition On The Bullet's Killing Mechanism

Part I: "Energy Dumping" Is A Myth

Let me state right here and now that there are two terms you're going to hear that have no meaning. If you haven't heard them yet, you will, if you spend any time at all on a shooting range or hanging around the wiseacres in gun shops. Both refer to popular myths among shooters about how a bullet kills, and are based on thorough misunderstanding of ballistics and biology.

"Hydrostatic shock" is the idea that a bullet kills by setting up a "shock wave" in the incompressible water of which an animal's body is largely composed. "Energy dumping" is the concept that if a bullet stops within an animal, it will kill more effectively than one that goes through and exits, since it "releases its entire amount of energy within the body."

As intuitively appealing as these notions are, the fact is that a bullet kills the same way any other agent of penetrating trauma does. A bullet may act faster than a knife or an arrow, but like them it kills either: 1) by causing a rapid loss of blood pressure, depriving the central nervous system of oxygen; or 2) by physically interfering with nerve pathways; or 3) both.

The False Reasoning Behind The "Energy Dumping" Fallacy

The bullet does indeed have a good deal of kinetic energy, and the faster it's moving the more it has, of course. In the USA bullet energy levels are rated in "foot-pounds", a relatively obscure unit implying the amount of energy needed to move one pound of weight one foot. European countries use the much more sensible metric system, and in this system the energy unit is the "joule". While both these units refer to energy of movement, the joule has the advantage that it can easily be converted to units used to measure heat. One calorie is equivalent to 4.1 joules, the calorie being a unit of heat. Specifically, one calorie is the amount of heat needed to raise one gram of water one degree Celsius. (The comparable unit in the US system is the BTU, but converting foot-pounds to BTU's is not so straightforward as converting joules to calories.) A bullet fired from a reasonably powerful handgun, say a hot 9mm Parabellum load, has an energy level of perhaps 500 joules at the muzzle.

So why do I care about converting muzzle energy figures into heat? Because if a bullet is stopped in its target, that's exactly what happens: its residual kinetic energy is, in fact released (or, as the wiseacres have it, "dumped") into the animal's body; but it's released as heat, in accordance with the laws of thermodynamics. (This is the reason why your car's brakes heat up when you stop: that energy can't be destroyed, it can only be converted to another form, and the "default" is to convert it to heat.)

The amount of heat liberated by stopping a bullet is surprisingly small: 500 joules works out to be about 106 calories. That would be enough to raise 106 grams (about 0.25 pounds) of water one degree Celsius (about 1.8 degrees Fahrenheit). That's not all that much, especially when compared to the size of animal it has to be "dumped" into. A man is a pretty large animal (about the size of a deer) and 500 joules (or 106 calories) of energy diffused through the body of a 150-pound (68,100 gram) human would not suffice to raise his body temperature even one-one-hundredth of a degree Fahrenheit. And that is a maximum amount, which assumes the bullet is stopped and that the shot was fired at point-blank range. To have a noticeable effect on tissue temperature you would have to "dump" a great deal more energy than 500 or so joules: the amount of heat liberated even by the biggest and baddest bullet available is very far below the capacity of the body's water to absorb it. It should be obvious, then, that the theory of "energy dumping" is based on an exaggerated idea of how much energy a bullet actually has, and is meaningless as a part of the killing mechanism.

Believers in the "energy dumping" theory never seem to have an adequate explanation for the fact that many, many gunshot victims are still walking around with bullets that "dumped" all their energy, and are still inside the victims. Many people with such retained bullets received them at close range from large-caliber guns, and were therefore the unlucky recipients of lots of "dumped" energy, but they are still alive. The answer, however, is really very simple: they are still alive because they were lucky enough not to have received a hit in a vital area.

Part II: "Hydrostatic Shock" Is An Even Bigger Myth

Proponents of the "hydrostatic shock" theory usually argue that animals are composed largely of water, and therefore a bullet causes a "shock wave" to be set up in them, which causes displacement of organs, and rupture of tissues. Their belief in this concept is bolstered by the spectacular splashes that expanding bullets make when fired into plastic milk jugs filled with water: they imagine that something of the same thing happens in an animal body. They are wrong.

First, animals aren't jugs of water, and don't resemble jugs of water in the least. Animals don't have uniform internal density, and the response of muscle to a bullet is very different than that of, say, the bones or the lungs. At the microscopic level, animals are actually very compartmentalized, and there is almost no "free" water (or any other liquid) to constitute a homogeneous medium in which a "shock wave" can be propagated for more than few millimeters. About the only places where large quantities of fluids are found sloshing around are in the spleen and liver, both of which contain sizeable volumes of "loose" blood.

Second, it has been demonstrated quite conclusively that most body tissues are very tolerant of momentary deformation and quite resilient. Unless a bullet physically cuts a blood vessel or nerve, little more than localized damage is done by its passage. It is true that in passing through, a bullet does form a so-called "temporary wound cavity" of considerable size, which lasts for milliseconds. Inside this volume a "shock wave" does form, and it even displaces some organs. But the effect of the temporary wound cavity is small, and most tissues and organs resist this very brief deformation. There is certainly no possibility--as you will frequently be told by ignorant gun shop clerks--that you can "...hit a man in the arm and the shock will travel through the blood to his brain and kill him..." Blood is carried in blood vessels, and those vessels are tough. Anyone who has dissected a freshly-dead animal will testify to the strength of an artery: it takes a good deal of force to rupture one, and physical displacement for a few milliseconds isn't enough. It's perfectly possible to displace an artery by several inches permanently with no loss of function. To do significant damage the artery has actually to be hit by the bullet, preferably by the sharp edges of the expanded outer jacket, which will cut it.

Furthermore, there is no way the "shock wave" could "travel through the blood" because the design of the system is such that a) it permits only one-way flow; and 2) it dampens pressure oscillations of considerable magnitude. Arteries that carry blood to the body are very muscular structures and designed to resist considerable heads of pressure lest they burst. And as they get smaller and smaller, ramifying to all the organs, the resistance to flow increases greatly. Even if you were to set up a significant "shock wave" locally, it wouldn't get very far in the system before the increasing resistance to its passage would dampen it out completely.

The True Believers in the "hydrostatic shock" myth often point to the messy soup found inside the chest of deer hit in the lungs as "proof" they are right. But they are really pointing to a major hole in their argument. There isn't any "free" blood in the chest of any mammal: like blood elsewhere, it's in blood vessels.

The lungs are a sort of enormous capillary bed, with millions of small blood vessels lying between the gas-exchange surfaces. Most of the volume of the chest is air. The vast quantities of blood found in the chest cavity of a lung-shot animal weren't there when the shot was fired. The free blood found in the chest after a shooting got there because the bullet damaged the blood vessels running through the area.

An expanding bullet does a fearful amount of damage to the extremely delicate tissue of the lungs, but this region also includes major blood vessels (the aorta and pulmonary artery, to name two) which are usually damaged as well. These pour enormous quantities of blood into the thoracic cavity when they're ruptured. Contraction of the body musculature and the pumping of the heart (if it too isn't hit) will assure this. The blood in the chest cavity is the result of the damage, not the cause of it, and the "shock wave" isn't propagated through it at all.

[Cyrille]

So, even a close range say 10 to 20 feet, bullet impact has no bearing on movement of the object struck; is it simple physics that determines this? "for each action there is an equal and opposite reaction"; i.e. the force that pushes an object would have to exert the same amount on the catylist thus causing the catylist to be moved in the opposite direction? So the scene in the movie "Shane" when Wilson [Jack Palance]  shoots  the character {Stonewall} is pure Hollywood make-believe; the impact of the bullet from "Wilson's" revolver on "Stonewall" would not move him at all and the kinetic energy of the projectile would be absorbed by the body and it would just fall where it stands. Makes sense I've seen deer shot that just fall on the spot and I've seen them run a few yards and collapse.

[LazyK Pejay]

If you have seen the MythBusters episode about a month ago they tested with a variety of high caliber rifles on a dummy to see if it would fly backwards with an impact. Truth is even with a 50 cal rifle at 25 yards the dumy did not fly back. It was knocked off its seat and fell down and in some case fell forward. The movie scenes are pure hookum.

In Vietnam I flew Huey guns for the Corps. On one of my early missions we caught a VC in the open who began to run. We rolled in and gave two bursts from our four M60's mounted on each side of the Huey. It did not blow him forward while he was running. He dropped and rolled forward (he was running, so it was that forward motion that contributed to the forward movement). He fell about three or four feet from where he was hit. If I have offended anyone with this scene I apologize.

Have a good day all.

LazyK Pejay

[Cyrille]

Thank you Mr. Pejay, That is what I suspected, after I recalled my deerhunting experances and reading Frenchie's post on the same subject.

[Hemlock Mike]

Remember action - reaction.  My old friend Mr. Newton had a law. 
If the gun firing the slug don't blow you on your a$$ -- Why would the target do the same ??

It's not the size of the hole but the placement 

Mike

[Cyrille]

Yeah, Mr. Mike, I don't know where "Wilson's bullet hit "Stonewall" But I do know it kilt him ded!

[law dawg]

Don't let Massaad Ayoob read this post, he's all about ++++++++p power corbon hollow points and shocking the central nervous system by shooting the perp in the solar plexus.

[Doc Shapiro]

Hey, if a bullet fired would throw someone back 20 feet, the recoil from that same gun must have been able to do the same thing to the shooter! 

[Cyrille]

Mr.Law Dawg,
  If'n Mr. Ayoob has acess to this thread, I don't know how we can stop him from seeing this! But'you're right  about his obcession with +++p power

[Cyrille]

Doc Shapiro:
Now, I didn't say that a bullet would knock someone back or in any direction for 20 ' or any amount of distance for that matter, I just asked if it would throw someone or some object in the opposite direction of  where the projectile was comming from when it hit. according to the answers I've received it would not because of the equal and opposite reaction law.

[Grapeshot]

A Living creature does not offer the resistance needed to be moved by a bullets impact.  Metal, most metals, do resist the passage of a bullet and will move to some degree or another based on the weight of the target and how it is anchored or attached to something.  Just look at a steel plate that's standing on a table and watch how it moves when hit by bullets.  Faster projectiles of varying weights will toss the plate differently IAW the speed and weight of the projectile.

Humans and other animals just flop when hit through the vitals.