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1 posted on 10/02/2007 9:15:52 AM PDT by 7thson
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To: 7thson

I dont think there is enough mass in a bullet or shot to physically move someone like in the movies is what their summation was.


2 posted on 10/02/2007 9:17:39 AM PDT by smith288 (Ohio State, close to being 2007 NCAA Champs)
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To: 7thson

The bullet delivers X foot-pounds of energy to the target, and that may be enough to unbalance someone or spin them around. Most of the reaction to a bullet hit is muscle retraction, which can cause some wild gyrations. A conventional small arms bullet doesn’t have enough kinetic energy to lift someone off their feet, but a .50 caliber Browning slug might encounter enough resistance in the body to give up enough energy to do that.


3 posted on 10/02/2007 9:20:55 AM PDT by Dumpster Baby ("Hope somebody finds me before the rats do .....")
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To: 7thson
The recoil from the weapon is your "equal and opposite reaction" - but you need a large caliber like a .50 or a 12-gauge slug from close range to knock someone down from the force of impact as opposed to simply putting them down from the physical trauma.

People certainly aren't sent flying backwards from being hit by a .38 round at 20 yards like they do in the movies.

5 posted on 10/02/2007 9:22:06 AM PDT by wideawake (Why is it that so many self-proclaimed "Constitutionalists" know so little about the Constitution?)
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To: 7thson
And two - they got the law wrong. I said that when you fire a gun the reaction is the recoil. And that when the bullet hits the person, the opposite reaction is getting pushed back.

Remember that I'm not a physicist, but I think your read here on the forces involved is correct. Also, the different kinds of ammunition can have different amounts of knockdown power. If they were shooting a high velocity rifle round with full metal jacket projectiles, there wouldn't be much blowback. Full metal jacket rounds tend to penetrate through their targets and not transfer as much energy to them (they just shoot through the target and keep going). Hollow points and round noses delivery much more of their kinetic energy to the target, and are more able to give you knockdown power.

This certainly wouldn't be the first time mythbusters has been completely full of crap, either.
6 posted on 10/02/2007 9:22:44 AM PDT by JamesP81
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To: 7thson

The premise of the Mythbusters segment was whether the force of a shot could make a human body fly backward through a window, as in a stereotypical cowboy “shoot ‘em up.” Their tests indicated no, and they used up to a .50 cal.


7 posted on 10/02/2007 9:22:45 AM PDT by 1rudeboy
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To: 7thson
they said that according to Newtons law - every action has an opposite reaction - that when the person gets blown back it would mean the shootist would get blown back the opposite direction.

Like This Guy?

8 posted on 10/02/2007 9:25:37 AM PDT by vbmoneyspender
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To: 7thson

What did the video show?


10 posted on 10/02/2007 9:27:41 AM PDT by stuartcr (Everything happens as God wants it to.....otherwise, things would be different.)
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To: 7thson

7thson,

Sorry, but it is a myth. For every action there is an equal reaction. That is true. But when continplating force, we must consider mass. The force of a bullit is large for it’s mass. The reason? Speed! That re-coil you feel when firing a .357 is the reaction from the blast of the charge. A bullit stopping quickly in a human body indeed does transfer that energy. However, the body is much more massive than the bullit and abosrbs this energy internally (organs get moved, tissue tears, etc.)

Consider, in terms of dangerous kinetic energy, what is more lethal. A 200 car freight train fully loaded moving at toward you at 10 MPH or a .357 fired at you at 10’.

You will not stop the train no matter what you do. You will propbably stop the bullit. But the impact force will not knock you down.


13 posted on 10/02/2007 9:31:44 AM PDT by Tenacious 1 (No to nitwit jesters with a predisposition of self importance and unqualified political opinions!)
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To: 7thson
Not all Mythbuster science is good science ... most physics sites that have discussion boards/forums will show that.


14 posted on 10/02/2007 9:31:53 AM PDT by Daffynition (The quieter you become, the more you are able to hear.)
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To: 7thson

There are movies on the internet showing what happens to a terrorist when he gets hit with a .50cal sniper shot. These are single bullet hits and the bodies get tossed by the force of the impact.

The mythbusters probably used a .22


15 posted on 10/02/2007 9:33:43 AM PDT by Diplomat
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To: 7thson
I believe in that episode they used up to a 12 ga slug before the pig was knocked hard enough to be disloged from the balanced hook it was suspended from.

Take the .44 Mag for example.

Despite its legend as a real powerhouse, it's important to understand that the .44 Mag is not really a "powerhouse" in hunting cartridge terms. The "standard" fast factory load uses a 240-grain bullet at 1,350 fps for 971 ft-lbs of energy

For every action, there is an equal and opposite reaction. If there are 971 ft-lbs of energy imparted to the bullet, then there are 971 ft-lbs of energy imparted to the shooter's hand.

When the bullet strikes it's target, assuming it is stopped by the target, then 971 ft-lbs are imparted to the target.

Now, if 971 ft-lbs is not enough energy to throw the shooter back 20 feet, then it is not enough energy to throw the victim 20 feet either.

16 posted on 10/02/2007 9:34:28 AM PDT by Yo-Yo (USAF, TAC, 12th AF, 366 TFW, 366 MG, 366 CRS, Mtn Home AFB, 1978-81)
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To: 7thson

I think for most bullets in most situations, Mythbusters got it mostly right.

While some bullets carry a great deal of energy, the other element to consider is how *fast* and how completely that energy is imparted in the target.

Highly frangible bullets will decelerate quicker and deliver more force over a shorter time. A solid lead, or better a jacketed bullet will travel further and decelerate over a longer period of time, spreading that energy over more time.

But in any case, the effect is not going to be so much that it will pick up somebody and toss them backward through a window or anything like that.

Some people that’ve been shot (I’m not one of them) say that it’s more or less like being whacked hard with a baseball bat. It certainly may make you fall down, but not fly through the air.


18 posted on 10/02/2007 9:37:15 AM PDT by Ramius (Personally, I give us... one chance in three. More tea?)
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To: 7thson
I am afraid Mythbusters is correct - if a bullet’s kinetic impact could knock a person back, it would do the same - or worse - to shooter.
People do react to being shot - that might be the source of stories about “knockback.” Read a story about somebody reacting to an itty-bitty .25 ACP hitting his vest like he’d been hit by a baseball bat.; in reality, it was all in his head - he knew what was happening. Contrast this to Reagan, who didn’t even know he was shot!
“Knockdown power” is more about tissue trauma - how big the wound channel is - that it is about kinetic energy dumped into to the target. Disrupt enough vital organs and the target falls down - and dies!
25 posted on 10/02/2007 9:59:41 AM PDT by Little Ray (Rudy Guiliani: If his wives can't trust him, why should we?)
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To: 7thson

depends on the caliber of the round and the type of round.

You get hit with a .22 you’re body is not going to go backwards

You get hit with a .45 you’re going to go back and down.


27 posted on 10/02/2007 10:05:56 AM PDT by Leatherneck_MT (A nation of sheep will beget a government of wolves.)
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To: 7thson

I reckon it would depent in no small amount upon whether the bullet exits the body or not. if it does not exit the body, then it’s entire energy is transferred to the body and the mass/acceleeration thingie kicks in.
if the bullet goes through the body, then some of the energy is absorbed by the body, and the remainder remains with the bullet.
there’s a classic picture of a bullet passing through an apple. the debris etc., is such that if you didn’t see the projectile in the pic, you couldn’t tell from which direction it came.


28 posted on 10/02/2007 10:18:02 AM PDT by camle (keep your mind open and somebody will fill it full of something for you)
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To: 7thson

30 posted on 10/02/2007 10:20:22 AM PDT by camle (keep your mind open and somebody will fill it full of something for you)
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To: 7thson

To oversimplify slightly: if it knocked down the victim, the recoil would knock down the shooter as well.

(”Knocked down” as in “blew him off his feet”, not “caused enough damage he couldn’t stand up”.)


31 posted on 10/02/2007 10:25:14 AM PDT by ctdonath2 (The color blue tastes like the square root of 0?)
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To: 7thson

Some observations:

There is a real effect that people think they are supposed to fall back or fall down when they get shot. People do this not because of the physics of the impact, but because of their muscle reaction, conscious or subconscious. The movies have had a big effect on this.

Recoil is comparable to “knockdown” power (assuming the bullet delivers all its energy to the target, and does not carry thorough with much energy remaining.) However, keep in mind that recoil is usually anticipated and braced against, while a bullet impact is not.

Imagine a “bullet catcher” weighing 200 pounds (Say, a steel plate on little car on rails). It is hit by a bullet weighing 1/10th pound (a 700 gr. 50BMG - conversion is 7000 gr./lb.) at 2600 feet per second, and all the energy is transferred to the target. The momentum of the bullet is transferred to the target, which weights 2000 times as much. Thus, the target will end up moving backwards at 1/2000th the velocity of the bullet, or 1.3 feet per second, or about 1 mph, which is a very SLOOOW strolling speed. But enough to make a guy fall backward, when he has just been traumatized.


32 posted on 10/02/2007 10:27:48 AM PDT by Atlas Sneezed ("We do have tough gun laws in Massachusetts; I support them, I won't chip away at them" -Mitt Romney)
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To: 7thson

Having been shot once (7.62x39 through the right shoulder), it hurt like hell, but didn’t knock me down or even spin me around. However, the first time I ever fired a .50BMG Barrett, I did it standing (on a dare),it knocked me flat on my ass.


40 posted on 10/02/2007 11:23:47 AM PDT by P8riot (I carry a gun because I can't carry a cop.)
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To: 7thson
Mythbusters got it pretty much right (you might get shoved back but you won't fly through the air) but there are so many variables involved that a categorical statement is or should be impossible. Recoil, for example. Yes, power generated by a firearm is subject to Newton's second law, (which is probably unconstitutional but there you are). However, toward the shooter that force is distributed through the recoil system of the firearm, which serves to draw out the force over time, and the mass of the firearm as well as the shooter. The target receives the entire force through the cross-section of the projectile, a far smaller and more intense distribution. Same force, smaller area, shorter time.

To make it more complicated, not all of the energy of the bullet is transferred to the target all the time. If it penetrates the target there will be residual energy. If not, not.

Can a shooter get knocked down by recoil? You better believe it, I certainly have been. First time I shot a 12-gauge I was standing on a slick surface and my feet went out from under me. My brother thought it was funny to see me on my butt but I managed to keep the muzzle downrange and out of the mud. Too many witnesses to shoot him at the time, dang it.

I mention that to indicate how many variables there are in shooting in the real world. Shooting a fixed target in a laboratory isn't like shooting a crack-maddened mime on a unicycle when you're on roller skates yourself. At least I don't think so. Never tried it.

41 posted on 10/02/2007 11:42:20 AM PDT by Billthedrill
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