The truth about handgun knockdown power

[KenpoTex]

Good Article...it's written by a cop and largely addressed to cops, however the principles are the same for anyone who carries a gun.
Here are a some exerpts to whet your appetite (emphasis is mine).



There is undoubtedly no other myth more perpetuated and closely held (even now) by many law enforcement professionals than what I have previously referred to as the “Demonstrative Bullet Fallacy,” or in plainer terms, the idea that any handgun of any caliber has “knockdown power,” in that the sheer size and force of the bullet can knock a person down. Closely related is the myth that bullet size — rather than shot placement — can determine or ensure a “one shot stop.” Both are inaccurate, unscientific, and dangerous, and have no place in the training of law enforcement professionals.*
*Or anyone else...




These so called [knockdown power] studies are further promoted as being somehow better and more valid than the work being done by trained researchers, surgeons and forensic labs. They disparage laboratory stuff, claiming that the “street” is the real laboratory and their collection of results from the street is the real measure of caliber effectiveness, as interpreted by them, of course. Yet their data from the street is collected haphazardly, lacking scientific method and controls, with no noticeable attempt to verify the less than reliable accounts of the participants with actual investigative or forensic reports.


http://www.policeone.com/police-products/firearms/articles/1757987-P1-Exclusive-The-truth-about-handgun-knockdown-power/

[Blindside]

To quote my CCW instructor with regard to the caliber wars, "all handguns suck."

[KenpoTex]

To quote my CCW instructor with regard to the caliber wars, "all handguns suck."

pretty much...a few instructors I know or have trained with say the same thing.

Of course my favorite is: "Pistols poke holes, long-guns tear **** up"

[Deaf Smith]

There is several ways to look at it.

Chuck Taylor:

http://www.chucktaylorasaa.com/stoppingpower.html


Evan Marshall and Edwin Sanow who wrote several books on the subject.

Martin Fackler (a well know surgeon and scientist):

http://en.wikipedia.org/wiki/Martin_Fackler

Mas Ayoob who has also compiled quite a few records of shootings and what seems to work better.

http://en.wikipedia.org/wiki/Massad_Ayoob

David Spaulding, a very well know LEO and trainer.

The upshot from all of them is, overall, more powerfull handguns TEND to work better toward a 'one shot stop' (and who shoots just one time???)

Better constructed bullets (read hollow points) TEND to work better toward that mythical 'one shot stop' round.

No one handed weapon can be guaranteed to produce a one shot stop except a sawed off 40mm grenade launcher with HE rournds.

Still, as they all have concluded, some are better than others. Lots better? Sure a .45 definatly is better than a .25.

9mm .vs. .45? The .45 is a bit better but the 9mm is so much easier to control.

9mm .vs. 40 .vs. .357 .vs. .45 .vs. the world? It all depends.

I would not lose sleep if all I had was a 9mm. I'd be unconfortable it all I had was a .25 though!

I am far more consearned about skill with what one has. Cause it's what you can do with what you've got that matters.

Deaf

[Sukerkin]

Intresting article and comments chaps. Once again, as a dis-armed Englishman, I applaud your passion for the, to us, denied art, of pistol shooting.

Even before the ban, I was a terrible pistol shot. The rifle was what I was good with. But I'm still always interested in what you fellows chat about in here :tup:.

[jks9199]

It's not a simple "this gun and this round" unless you've got a phaser or blaster in your arsenal, and ain't sharin'!

Most PDs have become less than impressed with the 9mm, even in any of the various hollowpoint rounds. That doesn't mean it's not effective; it's just not been as effective as they'd like. Many have gone to the .40 -- and let's be honest; there ain't that much of a difference between the two! Loads are ranging from 165 grain to 180 grain, depending on the department and specific round.

As trite as it sounds to say it... It really does come down to shot placement -- and the targets will to survive. I've seen the results of shootings where I can't figure out why the guy is still standing -- and others where what seems like a flesh wound that would barely need an ambulance, let alone an ER drops the guy DRT.

[Archangel M]

Do people still believe in pistol "knockdown power"???

[rmclain]

Most people only have firearms education from television and movies. I would put money on the fact that most of you posting have better education and experience to understand the reality of handgun capabilities. You're probably the person everyone hears laugh in a movie when a "bad guy" goes flying when shot by the "good guy's" handgun. I'm right there with you.

I re-invented the wheel (so to speak) in 2000 with a university research project through the kinesiology dept at UT-Arlington along with the help of FTW PD and FTW medical examiner's office. The study compared several handgun calibers (9mm, .40, and 45ACP) against several punches. This study was later put on file at the Library of COngress. But, it basically supported the numbers provided by the cartidge manufacturers and showed a comparison between potential knockback and "potential lethality."

As a general rule, the way I explain it to non-educated peple on the subject is, "Do you know the recoil you feel from the handgun? While the projectile is potentially lethal, the target actually experiences less recoil than your hand."

R. McLain

[MA-Caver]

By and large I think that most guns do have that one shot stopping ability... provided the round goes right to the head. Hitting center mass and you got more stuff to try and knock out... the heart is well protected and hard to hit on a moving target... yes, so is the head, but hit the skull and penetrate the brain and things generally stop happening up there.
We keep aiming for center mass because it's the easiest to hit and we don't really want to kill. Practice aiming for the head and you got your one shot stop right there. IMO


or maybe I've been watching too many Zombie movies???

[zeeberex]

By and large I think that most guns do have that one shot stopping ability... provided the round goes right to the head. Hitting center mass and you got more stuff to try and knock out... the heart is well protected and hard to hit on a moving target... yes, so is the head, but hit the skull and penetrate the brain and things generally stop happening up there.
We keep aiming for center mass because it's the easiest to hit and we don't really want to kill. Practice aiming for the head and you got your one shot stop right there. IMO


or maybe I've been watching too many Zombie movies???


Im happy with a mossberg 500 pump action, simple, affordable,and has decent boomage

[arnisador]

Do people still believe in pistol "knockdown power"???

I know plenty who believe in it because they are certain it creates a "hydrostatic pressure wave" that "disrupts the nervous system" essentially independent of the size and construction of the round. This seems contrary to intuition and experience to me.

[Deaf Smith]

Guys,

The Texas Department of Public Safety uses the .357 Sig round. According to a good friend who is in forensics there, they are very very happy with the round and it has over a 90 percent one shot stop rate there.

They used to use the .45 ACP, and while they liked it, they said it didn't have the 'lightning bolt' effect the old .357 Magnum did. The Sig round basicly duplicates the 125gr JHP load the .357 Magnum's reputation was built on. Oh, and another reason they went to the .357 Sig was the weapon itself. The Sig 226 was easier for most people to hold and shoot than the 220 in .45 ACP.

Now nothing is 100 percent as for handguns, but yes some do tend to do better than others. And different bullet construction tend to give different results to. And if you have one of the top rounds and it has very good bullet construction, then the only real weak link is the shooter (and isn't that always the case?)

Deaf

[KenpoTex]

By and large I think that most guns do have that one shot stopping ability... provided the round goes right to the head. Hitting center mass and you got more stuff to try and knock out... the heart is well protected and hard to hit on a moving target... yes, so is the head, but hit the skull and penetrate the brain and things generally stop happening up there.
The problem is that pistol bullets have the nasty habit of frequently glancing off or "riding" the skull and not penetrating. The actual target area on the head (when the BG is facing you) is going to be the ocular-nasal area where there is easier access to the brain. Hitting the frontal bone or occipital bone may or may not do much. The target area is basically between the upper lip and the brow line.
Another way to address the problem has been proposed by (IIRC) John Farnam who advocates changing the classic "Mozambique drill" (2 to the chest, 1 to the head) to chest and throat. This way, you still have a chance of causing CNS shutdown by hitting the spine without having to contend with the skull. different strokes and all that...


We keep aiming for center mass because it's the easiest to hit and we don't really want to kill. Practice aiming for the head and you got your one shot stop right there. IMO


or maybe I've been watching too many Zombie movies???

??? If you hit the proper target area (heart, lungs, aorta, etc.), you will inflict life-threatening damage. If I have to shoot someone, I'm not going to just shoot them in a vague "center mass" area, there is still a specific area we want to hit. Granted, this target area is larger than the target area of the head, thereby making it a little easier to hit. However, wanting to kill or not wanting to kill don't really enter into the discussion...

[MA-Caver]

The problem is that pistol bullets have the nasty habit of frequently glancing off or "riding" the skull and not penetrating. The actual target area on the head (when the BG is facing you) is going to be the ocular-nasal area where there is easier access to the brain. Hitting the frontal bone or occipital bone may or may not do much. The target area is basically between the upper lip and the brow line.
Another way to address the problem has been proposed by (IIRC) John Farnam who advocates changing the classic "Mozambique drill" (2 to the chest, 1 to the head) to chest and throat. This way, you still have a chance of causing CNS shutdown by hitting the spine without having to contend with the skull. different strokes and all that...



??? If you hit the proper target area (heart, lungs, aorta, etc.), you will inflict life-threatening damage. If I have to shoot someone, I'm not going to just shoot them in a vague "center mass" area, there is still a specific area we want to hit. Granted, this target area is larger than the target area of the head, thereby making it a little easier to hit. However, wanting to kill or not wanting to kill don't really enter into the discussion...
Well, I think that it should... even in terms of knock-down power... I mean what is the intent when you shoot someone... to stop them... but do you want to kill them or do you want to maim/wound/hurt them?
A vietnam vet told me that the officers were issued a replacement for their standard 1911 .45's to the newer 9mm guns but found in the field that the 9mm didn't have the stopping power of the .45 when a infantry charge of NVA's came at them... so officers voluntarily made the switch back.
Dunno if that is true but it sounds very good... :D

Either way... shooting someone does take a lot of thought (even within a millisecond) and yes, I think in this matter... size does make a difference in knock down power.

[jks9199]

We keep aiming for center mass because it's the easiest to hit and we don't really want to kill. Practice aiming for the head and you got your one shot stop right there. IMO

I missed this the first read, and feel that it's worth addressing.

We shoot for center mass for several reasons -- but NONE OF THEM are because we don't want to kill. It's a nice thought -- but if cops are using lethal force, they believe that the threat is life and death, and should be responded to in like manner. This applies at least equally to civilians defending themselves!

We shoot center mass because it's an easy rule; you always aim for the center of the VISIBLE mass, even if that's only a head and shoulder. Center mass is generally a pretty big target, making a hit more likely under the effects of adrenal stress. We shoot center mass because it's likely to have the desired effect of stopping the threat; there are lots of organs and major blood vessels and so on that tend to give us hope that we'll accomplish our goal quickly. And we shoot for center mass because most of us don't have the luxury of spending thousands of rounds and the hours involved in training to have the skill under pressure to be really picky about targets. And we shoot center mass for the simple reason that it works... (I'm sure there are some more reasons... but those are a good start.)

What we don't do is shoot center mass hoping to merely wound.


or maybe I've been watching too many Zombie movies???

Are they the new fast walking zombies? ;)

[KenpoTex]

Well, I think that it should... even in terms of knock-down power... I mean what is the intent when you shoot someone... to stop them... but do you want to kill them or do you want to maim/wound/hurt them?
A vietnam vet told me that the officers were issued a replacement for their standard 1911 .45's to the newer 9mm guns but found in the field that the 9mm didn't have the stopping power of the .45 when a infantry charge of NVA's came at them... so officers voluntarily made the switch back.
Dunno if that is true but it sounds very good... :D

Either way... shooting someone does take a lot of thought (even within a millisecond) and yes, I think in this matter... size does make a difference in knock down power.

I must have been unclear on what you were saying...it sounded like you were saying we shoot for center mass because we don't want to kill them, which is what I was addressing.

If deadly force is used, we target the areas that will stop them as quickly as possible...unfortunately (for them) that means that there is a high chance of killing them.

[Archangel M]

There is a difference killing a guy with one shot and "stopping" a guy with one shot. A person hit once can keep on going and do signifigant damage before expiring. Thats not a "stop".

[jarrod]

who cares about the one stop shot? why just shoot them once? two in the chest, one in the head. that's how i was taught.

jf

[GBlues]

My father, and grandfather always told me, if you pull a weapon (i.e. a gun) use it. THere is no reason to pull a pistol, rifle, any firearm or weapon unless you feel that your life is in danger. If your life is in danger you'd better kill the s.o.b, cause if you don't you might be like the wanna be biker that got chased around the bar room pool table, screaming "Stop or I'll shoot!", nope he never did, and got the crap kicked out of him for pulling a firearm on a guy. Saw that happen to a guy when I was about 5 years old. Valuable lesson to be learned there.

Anyways, I have always like the .45 long colt. My grandfather was a deputy sheriff, in the state of arizona, he used a .44 magnum in those days. Once he shot a man in the back with it, the guy ran another 20 yards, so my grandfather claimed. So he switched to .357 and next time he had to use it, he hit a guy and threw him another 20 yards. Swore to his dying day that a .357 beats a .44 for knockdown power everytime. I don't know, I've never had the misfortune to have to find out, and hope I never do.

[KenpoTex]

I give up...

[Deaf Smith]

If you hit the proper target area (heart, lungs, aorta, etc.), you will inflict life-threatening damage. If I have to shoot someone, I'm not going to just shoot them in a vague "center mass" area, there is still a specific area we want to hit. Granted, this target area is larger than the target area of the head, thereby making it a little easier to hit. However, wanting to kill or not wanting to kill don't really enter into the discussion...

Guys,

I want you to listen to what Kenpo is saying. Yes the 'COM', center of mass, is a poorly definded area. It emcompases basicly the edge of the lungs (which is quite a bit of area) and on down past the diapharm. Alot of that area is not immediatly vital.

I've always felt the COM bit was a way to help explain poor marksmanship. Everyone shot COM and thought they were good shots and it would do the deed. But, just to much of that COM is not so vital.

Center of lungs, yes. Heart, yes. And nothing else. We are talking about the size of a grapefruit and nothing more!

Now about stopping power. I hate the term 'knock down power' cuase short of a full dose from a double barrel 10 gauge with 3 1/2 inch magnum buckshot there is no 'knock down power' (and belive me, two barrels of a 10 guage will just about knock down the shooter to!)

Stopping power is the ability to stop an aggressor, right there. One has to depend on hitting that grapefruit do to this with a good round. Failure to do this, even with the vaulted .44 magnum may very well not phase the attacker, who then will try to pay you pack.

And this is why marksmanship is so important. And why I don't gripe with Kenpo using a 9mm. The 9mm will do the deed if you shoot well, and happly the 9mm, due to low cost and low recoil, is easy enough to learn to be that good.

But if you have the money, time, and dedication, then a larger, more powerful round would be helpful just in case you can't quite make that grapefruit size shot in a hurry.

But reguardless if you pack a 9mm, .40, or .45, the abilty to shoot strait and shoot fast, is the most important part of 'stopping power'.

Deaf

[jks9199]

Anyways, I have always like the .45 long colt. My grandfather was a deputy sheriff, in the state of arizona, he used a .44 magnum in those days. Once he shot a man in the back with it, the guy ran another 20 yards, so my grandfather claimed. So he switched to .357 and next time he had to use it, he hit a guy and threw him another 20 yards. Swore to his dying day that a .357 beats a .44 for knockdown power everytime. I don't know, I've never had the misfortune to have to find out, and hope I never do.

I'm sorry -- but that story is crap. For a handgun to pack enough force to not only strike the target, but knock it 20 yards would require that it have enough recoil to throw the shooter back, too. Basic Newtonian physics.

Ain't gonna happen. It's possible that the guy he shot fell, it's possible he lost his balance... but he wasn't thrown 1 foot, let alone 20 feet by a round from a handgun. Heck -- if you don't hit a popper target right, it won't spin... and they're a lot lighter than a person!

[Grenadier]

In terms of physics, people don't get thrown around when hit by a handgun bullet. There's simply not enough physical momentum, even for a rifle bullet, to blow someone back any significant distance, despite what Hollywood says.

For those who want to try an interesting experiment, I would challenge them to get a side of beef, or a hog carcass that weighs about 120 lbs. Set it standing on top of a box, and shoot it with a single handgun bullet, even a .44 magnum.

Even anti-gunners who let go of the "guns are powerful hand cannons" philosophy, will understand, that the carcass isn't going to go flying any significant distance at all, except maybe to tip over.

The owner of Second Chance Body Armor, even demonstrates his products, by wearing them, and getting shot by calibers that they are rated to withstand.

I'm sure that his demonstration of a .44 magnum slug hitting him while wearing the vest (and causing no knockdown or knockback at all), and only resulting in a slight grunt from him, is somewhere on Youtube or Google vids.

[Grenadier]

Here we go:

http://www.youtube.com/watch?v=aaS_2l8nGdg

It's a bit old, but he's firing .308 Winchester / 7.62 mm NATO ammo.

This round generates 2700 ft lbs / s^2 of kinetic energy, maybe more, which is far more than any handgun round, including the Dirty Harry .44 magnum. The guy is standing on one foot, and doesn't get knocked over at all, despite all of the energy being dumped into the target.

5 minutes into the video, you can even see how a .44 magnum (far weaker than the above rifle round) has virtually no effect on someone's positioning.

Thus, Hollywood is woefully ignorant about firearms, and it's no wonder why many actors embrace the "guns are baaaaaaaad" mantra.

[Brian R. VanCise]

Shot placement is a top priority when having lethal force incident with a firearm. No doubt someone with a 9mm, .40cal, .44 or .45caliber will be successful if their placement is good. http://www.martialtalk.com/forum/images/icons/icon6.gif

[Grenadier]

There is a difference killing a guy with one shot and "stopping" a guy with one shot. A person hit once can keep on going and do signifigant damage before expiring. Thats not a "stop".

QFT.

We need only look at the North Hollywood shootout of 1997:

http://en.wikipedia.org/wiki/North_Hollywood_shootout

The bad guys, despite being heavily armored, had at least 10 wounds from gunfire, and still kept fighting.

[punisher73]

I believe Mythbusters even did an episode on this hollywood myth and busted it. I don't agree with some of their results but this one was pretty straightforward. Their conclusion, even when shooting with a shotgun there wasn't the big throwback to a person like you see in the movies.

I have also heard the story about the .45 being issued to marines in the Phillipines due to it's "stopping power". This is kind of a slight twist of the reason why some rounds are used or not used. It is based on round velocity and passthroughs.

For example, if I am in LE and have to shoot someone, I am responsible for every bullet that comes out of my gun. I want to make sure that the round I am using will do the most damage while hitting the target, and at the same time staying where I put it. This is the reason many departments switched to a .40 caliber round instead of the 9mm round. The 9mm doesn't always transfer it's energy into the target and passes through it. A slower round tends to transfer it's energy into the target (the bullet expands and stops in the target) instead of going through it like a fast round can. If I have a round, I WANT the bullet to expand because it creates a bigger more damaging wound channel, if the bullet does not exapnd I only create a wound channel the same diameter as the round and the quick pass through may not cause much damage. Military rounds have been designed before that pass through so you CAN hit more than one person if the round goes through which gives you "more bang for the buck" so to speak.

Here is a quick comparision between the most common LE rounds

.45 ACP on average 800-1000 feet per second
.40 S&W on average 700-1000 feet per second
9mm on average 1000-1400 feet per second

Now factor in that many departments have one gun that is given to officers. You have to take into consideration magazine capacity and the average officer's hand size. The .40 is only a little bit bigger than the 9mm, but as you can see has almost the same velocity as the .45 ACP. Many people complain that the size and kick of a .45 is too big. The .40 has only a little bit more recoil than the 9mm and about the same size so it is very manageable for the average officer. This is the reason that many departments have switched to the .40, it was less likely to pass through the target like the 9mm, but it was not based on "knockdown" or "stopping power" (unless you are referring to the bullet stopping).

[jks9199]

I've also been told that the military WANTS that pass through... After all, a wounded soldier takes at least one, maybe two more out of the fight tending to him. In LE, as you said, we don't want the rounds going anywhere but into the bad guy.

[thardey]

I'm not sure which book it was, but I think it was "Kill or get killed" by Col. Grossman. (It was the one that worked with some Asian police dept.)

He noted that when criminals got shot in the stomach, they had a tendency to drop their guns and clutch their stomach, since the stomach wounds were a lot more painful. When they were hit in the chest, unless it hit the heart specifically, they often didn't react to being shot.

Not long after I read that book, my Dad went to the hospital for heart burn, but wanted to make sure that it wasn't a heart attack. (Turns out he was okay). But the nurse explained (in a very simple version) that the reason that heart attacks feel like heartburn is that our brains don't distinguish between damage cause in our chest area, that is, the pain nerves are sort of wired on "one channel" so our brain just knows that our chest hurts. Damage to the heart is translated the same as heartburn, and doesn't necessarily hurt that much.

On the other hand, our stomachs are very sensitive to damage, and cause a lot of pain, even though it is less lethal. (Stomach cramps will double me over in a heartbeat). Of course, the pain factor is only an issue when dealing with someone who can still feel pain, and not someone who is drunk or high, and can't feel anything.

What have you guys heard about this? What do you think?

[Deaf Smith]

I've also been told that the military WANTS that pass through... After all, a wounded soldier takes at least one, maybe two more out of the fight tending to him. In LE, as you said, we don't want the rounds going anywhere but into the bad guy.

Hauge convention, which we signed, prohibits 'dum-dum', that is any bullet designed or made to expand and magnify the damage.

Of course we got past that by using shape pointed bullets that destabalize and tumble upon impact (and some desentergrate.) Thus causing much more damage than one that just shoots through.

FMJ handgun bullets do not have that ability to fragmentate but will tumble. But being so much blunter and shorter, they don't add that much to the damage.

Deaf

[Grenadier]

Hauge convention, which we signed, prohibits 'dum-dum', that is any bullet designed or made to expand and magnify the damage.

Ah, but we, the USA, never actually signed onto that original accord.

http://www.thegunzone.com/hague.html

The reason why the military uses ball ammo is due to the fact that you get the most reliability with ball ammo.



Of course we got past that by using shape pointed bullets that destabalize and tumble upon impact (and some desentergrate.) Thus causing much more damage than one that just shoots through.

Not so much the tumbling aspect... Military rifles use a fast enough twist rate, that even the heaviest 5.56 mm NATO rounds will be stabilized from their barrels. Where we get some really nice performance, though is with thin jacketed FMJ rounds, that fragment in a fluid medium, when a critical velocity has been reached.



FMJ handgun bullets do not have that ability to fragmentate but will tumble. But being so much blunter and shorter, they don't add that much to the damage.

FMJ handgun ammo shouldn't be underestimated. The NYPD, prior to using the tried and true 124 grain +P Gold Dot JHP, used ordinary hardball ammo in their 9 mm weapons, and never had any complaints about its performance!

[Deaf Smith]

Grenadier,

The US is not a signatory to the Hague Convention, but we abide by most of it's provisions. Always have.

And the NYPD, in the Delito shooting, were they used FMJ, found it wanting. The NYPD's FOP demanded the JHPs. I don't even know of any police department in the U.S. that uses anything but JHPs.

Oh, FMJ can kill, and if hit just right, can stop, but it's well known it's not a good stopper (but if that's all I had, then that's what I have!)

Deaf

[Carol]

For example, if I am in LE and have to shoot someone, I am responsible for every bullet that comes out of my gun. I want to make sure that the round I am using will do the most damage while hitting the target, and at the same time staying where I put it.


I've also been told that the military WANTS that pass through... After all, a wounded soldier takes at least one, maybe two more out of the fight tending to him. In LE, as you said, we don't want the rounds going anywhere but into the bad guy.

Hence another reason for aiming for center mass, yes? The head is a small target that is likely to move around (one's eyes generally point in the direction that one is traveling), versus a larger target with less peripheral motion. Someone who is enduring a threat to their life needs to put a round in the bad guy, but also needs to ensure to the best of their ability that the round doesn't go in to an apartment wall, or otherwise astray.