Knock down/stopping power... Fact or Fiction?

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Testing has demonstrates that bullets traveling under 1800 - 2000 fps do not cause damage to vascular tissue with the temporary cavity, with the exception of the liver.
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Do you have a link to this testing? because I'm calling BS I've seen massive damage done to lung tissue by a 44mag and the bullet never entered the chest cavity. I've also seen many real tests. www.brassfetcher.com and www.ballisticstestinggroup.org which suggest remote wounding from temporrary cavity happens with less than 500 ft lbs of KE.
 
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You know, of course, that this subject has been discussed for the last 200 years, more or less. One would think all controversy would have been resolved by now. The technology keeps changing, though.

Fairbairn (or Sykes) said that the more he learned about the subject, the less sure he was about it. He even mentioned the direction people fell and wondered how much the bullet had to do with it. Ultimately he was not that dogmatic about it and instead concentrated on other things in his training, like getting hits in the first place.

Somewhere in his book he mentions holding a bulletproof shield and letting someone shoot at it. The impact of the bullet, which was probably a .45 ACP, hitting the shield was barely perceptible or similiar words. So, no, in the case of a pistol bullet and probably a lot of rifle bullets, there is no "knockdown power" in that sense, although on that point a little depends on the shield. In the case of soft body armor, however, there can be some trauma even in the absence of penetration. He did mention that being in front of the gun when it was fired was a little unsettling.

Still, one has to admit that some people (and other animals) will go down when they are shot and only because they are shot. I would call that knockdown power and that may the point of disagreement here. In fact, it also seems to be a major point of both confusion and controversy with the studies of Marshall et. al., though I suspect the underlying reason for most of it is merely because the results aren't pleasing to one's own ideas. My father, for instance, claimed that a .45 auto would knock you down if it hit you in the little finger. He I never disputed.
 
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I once shot a rabbit in the head with a .22LR HP from the side. The rabbit shot straight up into the air about 8' high, did a lazy little backwards somersault and then plopped to the ground dead. The rabbit didn't do that because the energy of the .22LR from a perpendicular angle flung it straight up into the air. It did that because the last electrical signals from its scrambled brain told the muscles to contract very strongly.

I'm guessing a lot of the "knockdown power" anecdotes probably describe similar phenomena.
 
Well, if getting hits in the first place is the key to stopping power (there being little if any power in a miss--except with a .45), then being shot has something to do with it.
 
pturner67 said:
...A 9mm to the chest and a non-superhuman person goes to the ground. Whether he is "knocked down" or just collapses, the result is the same....
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He falls down -- and not always.

There are four ways in which shooting someone stops him:

  1. psychological -- "I'm shot, it hurts, I don't want to get shot any more."
  2. massive blood loss depriving the muscles and brain of oxygen and thus significantly impairing their ability to function
  3. breaking major skeletal support structures
  4. damaging the central nervous system.

Depending on someone just giving up because he's been shot is iffy. Probably most fights are stopped that way, but some aren't; and there are no guarantees.

Breaking major skeletal structures can quickly impair mobility.

Hits to the central nervous system are sure and quick, but the CNS presents a small and uncertain target. And sometimes significant penetration will be needed to reach it.

The most common and sure physiological way in which shooting someone stops him is blood loss -- depriving the brain and muscles of oxygen and nutrients, thus impairing the ability of the brain and muscles to function. Blood loss is facilitated by (1) large holes causing tissue damage; (2) getting the holes in the right places to damage major blood vessels or blood bearing organs; and (3) adequate penetration to get those holes into the blood vessels and organs which are fairly deep in the body. The problem is that blood loss takes time. People have continued to fight effectively when gravely, even mortally, wounded. So things that can speed up blood loss, more holes, bigger holes, better placed holes, etc., help.
 
There is "knockdown power" in terms of steel target shooting and pinball shooting. In general, larger bullets have better "kockdown power" than smaller ones to topple targets.
 
A 9mm to the chest and a non-superhuman person goes to the ground. Whether he is "knocked down" or just collapses, the result is the same.
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Put a bullet proof vest on that same guy and watch him NOT being "knocked down."

No such thing as "knock down" power. Newton's law reigns!
 
People have continued to fight effectively when gravely, even mortally, wounded. So things that can speed up blood loss, more holes, bigger holes, better placed holes, etc., help.
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Then again it may not help any. if the first shot obliterates the heart causing complete cardiac arrest, more holes, bigger holes in the heart, lungs, kidneys or liver aren't going to speed anything up.
Funny thing is you probably wont be able to tell what you hit, weather his heart is stopped or not, because he may act like nothing happened and keep on going about killing you.
 
Knockdown Power

Having extensively tested all sorts of firearms, i witnessed a Volunteer Trainnee getting shot with a 308 at ten feet while he stood on one foot and it barely rattled him. He was wearing protection of course which didn't prevent him from getting a huge bruise. I on the otherhand got hit in my upperleft chest with a 45 Hardball which didn't knock me down either. So i beleive that the idea of ultimate knockdown may be a myth.
 
I had a great uncle, George, who was shot a dozen times with a .22 rifle. He took the rifle away from the shooter and literally beat him to death with it. George lived many years after that.
 
Someone posted a Youtube video of some idiot shooting himself in the abdomen with a 10mm to test a bulletproof vest over on the Sig forum... it doesn't knock him down, but clearly shows his stupidity.

I'd post the link here, but the language after he pulls the trigger is not suitable for general audiences.
 
A bullet can only physically impact as much force on the target as it did to the shooter during recoil. "knock down" power is pretty much a non-factor.
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No, it can exert far more force.
It cannot import more momentum than it did on the shooter.
Momentum is NOT the same as energy (ft-lbs) or force (lbs).
Conservation of momentum still works.

I don't understand why people don't believe there is such a thing as knockdown power.
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We passed physics and you did not?

I believe knockdown power does exist, but you have to stop the bullet from penetrating through and absorb all of the energy.
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A bullet does not have enough momentum to knock a person down.
If it did the shooter would be on his a** from firing the gun.

Momentum is conserved at the shooter and the victim.
 
There is "knockdown power" in terms of steel target shooting and pinball shooting. In general, larger bullets have better "kockdown power" than smaller ones to topple targets.
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Try a 150-200 pound steel target, or bowling pin!

The rest of you that keep insisting that there is such a thing should have skipped a few Hollywood Westerns, and studied your physics homework a little more.
A bullet isn't going to knock anybody down. It may make them fall down due to the reasons listed before, but not knock them down.

This is beginning to sound like the perpetual argument I have had with my brother-in-law that a bullet shot from a perfectly level barrel starts dropping as soon as it leaves the muzzle! It does, but that is for another thread...Please!!!
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There is no such thing as "stopping power" or "knock down power".
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There is both.

Knockdown is related to CNS response, and affected by shot placement as well as wound channel
hydrodynamics in interaction w/ the central nervous system

Stopping Power is a partially the effect of initial knockdown (if any), but emphasizes the immediate
/mid-term effects on major organ damage that contribute to continued mobility and life.
 
Ok, this is a constant battle some friends and I have. Is stopping/knock down power fact or fiction? I certainly don't want to get shot by any gun of any caliber, but I'd much rather get hit by a .22lr than a 500 Mag. So my question is this: is stopping power necessary? I'd like to hear some of your opinions before I give my own.
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I'd be more concerned with the shot placement than the caliber. Receiving a glancing shot from a 500 mag is more preferable to a center mass shot from a .22lr that hits vital organs.

You want to hear a real life story about large calibers failing to take out a BG with "knockdown power", check out the proarms podcast interview with chicago detective Bob Stasch-15 gunshot wounds from .45lc, .44mag, and .38spl put into a 5'7'' 145lb drug dealer, most at almost point blank range, most center mass. The eventual round that forced the guy to drop was a shot to his knee cap from a .44mag.

heck...here's the link. http://proarmspodcast.com/?s=bob+stasch
 
Knockdown is related to CNS response, and affected by shot placement as well as wound channel
hydrodynamics in interaction w/ the central nervous system
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That would be fall down.
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Negative. Gross insult to your CNS -- including distributed spinal areas -- can (and does) send the whole body into violent shock/spasm. It can act as if lightning has struck you and will literally/immediately "knock you down" flat and or propel you (by your own muscle reaction) across a space and into obstructions.

Google Zapruder to see it in well documented action.

Shot placement and induced hydraulic effects are critical factors
 
You could probably find, if you looked, on youtube or something like that a video of someone being knocked down when they fired a gun, usually a shotgun. However, in those cases, it was more a reflection of something unexpected happening that the shooter wasn't prepared for.

On the other hand, I do understand what people mean when they say that if someone goes down immediately upon being shot, they weren't literally knocked down, they just went down. But being shot may have had something to do with it, even if they weren't knocked down.

If this keeps up, pretty soon we'll conclude that no one ever dies from a gunshot; they just give up on their own and decide to die because that's what they thought they were supposed to do. Animals, of course, do not think that way and never die.

Or something like that.
 
Negative. Gross insult to your CNS -- including distributed spinal areas -- can (and does) send the whole body into violent shock/spasm. It can act as if lightning has struck you and will literally/immediately "knock you down" flat and or propel you (by your own muscle reaction) across a space and into obstructions.
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That isn't as much a function of the round used as it is the location of the impact.

You can hit a person just below the knee very lightly with a reflex hammer and get the leg to kick, but hit that same person directly on the patella with the same hammer significantly harder won't get a reflex action.

Unless that person slaps you for hitting them so hard.;)

I don't think anyone is arguing that there are physiological effects of ballistic impacts. The problem is that it isn't quantifiable to a specific A+B=C equation because the human body isn't a homogenous target.

If I shoot someone with a .45, the thought they will be jerked off their feet with the impact is patently false.

However, if that same .45 severs the targets spinal column, they will fall like a bag of rocks.

And to your point, if you hit the right never clusters/muscle groups the right way, you can cause a person to fall down.

Look at boxers with "Glass jaws".
 
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