Does temporary cavity do damage?


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FerFAL
September 14, 2007, 05:02 PM
More proof that confirms what we already know.
“Temporary cavitation from this round broke the wooden board that the block was sitting on, into two pieces lengthwise.”
http://www.brassfetcher.com/Speer240grainJHP.html
FerFAL

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Vern Humphrey
September 14, 2007, 05:09 PM
Yep -- you can break boards that way.:p

MCgunner
September 14, 2007, 05:09 PM
Don't mess with Harry Callahan....:evil:

Obiwan
September 14, 2007, 05:46 PM
From the FBI HWFE report

CaesarI
September 14, 2007, 05:47 PM
As my medievalist wife likes to say: "It varies".

Two factors impact the wounding ability of a temporary cavity:
1. Type of tissue being penetrated.
Some tissue is more elastic than other tissue. Muscle tissue is more elastic than brain tissue. More elastic tissue requires a larger temporary cavity before you will see damage caused by a temporary cavity.

2. Size of the temporary cavity.
This factor is directly tied to the first factor. A temporary cavity that has no effect on muscle tissue, can have a dramatic effect on brain tissue.

These two factors explain why watermelons explode (not very elastic) and why properly calibrated ballistic gelatin does not (more elastic).

I appreciate the service Brassfetcher is trying to do, testing ammunition is very expensive. I can sometimes get reasonable estimates from the data they post, unfortunately sometimes this is impossible as their methods are not as thorough, and hence, not as accurate as they could be.

Breaking of boards during testing is very common when some people mistakenly test rifle rounds in gelatin blocks that are sized to handle pistol rounds. Sometimes this effect is also seen when people test particularly powerful handgun rounds. It should not be taken as evidence that the currently available information regarding the damaging potential of the temporary cavity is somehow flawed.

The "temporary cavity is king" school of thought was believed by some government researchers until the late 80s. The method of evaluation was the NIJ's RII (Relative Incapacitation Index). It was a very, very simple method of evaluating bullet performance, much simpler than currently accepted methods. It was also easy for the amateur to model. The same is much less true of current testing methods.

-Morgan

ranger335v
September 14, 2007, 06:13 PM
Tissue damage counts. What tissue it is and how badly it's "temporary disrupted" counts too. Caesar's wife has it right, as usual with questions like this, there is no clear answer.

Vern Humphrey
September 14, 2007, 06:17 PM
A temporary cavity that has no effect on muscle tissue, can have a dramatic effect on brain tissue.
Yeah -- but the target is already dead.;)

CWL
September 14, 2007, 08:21 PM
Typically only rifle ammunition can cause temporary cavities that are large enough to do damage, and it still depends on the elasticity of the particular tissues/organs being stretched. Pistol bullets in general do not create temp. wound cavity large enough.

Soybomb
September 14, 2007, 09:54 PM
More proof that confirms what we already know.
“Temporary cavitation from this round broke the wooden board that the block was sitting on, into two pieces lengthwise.”
Thankfully I have no wooden organs.

Cosmoline
September 14, 2007, 09:57 PM
From a high powered rifle, YES. Vis:

http://www.barnesbullets.com/videos/308_180gr_TSX_6fps_logo.wmv

From a slow speed handgun, not so much.

GunTech
September 14, 2007, 09:58 PM
The rule of thumb (according to several sources quopted in SIPRI's 'Antipersonnel weapons') is the round must have at least a velocity of 600m/s before cavitation has any discernable effect. As noted, the organ struck also has a huge bearing. Muscle is fairly resistant to stretch, the liver isn't.

Hoppy590
September 14, 2007, 10:08 PM
id hardly say "knock down power is a myth" when you get hit by a truck very little penetration takes place :p
in handgun rounds, this is probibly negligable. but i wanted to make that truck joke

mavracer
September 14, 2007, 10:49 PM
is the round must have at least a velocity of 600m/s before cavitation has any discernable effect.
no
the round must have at least a velocity of 600m/s before cavitation has a consistant meaningful effect.there's almost always a discernable effect there is damage larger than the expanded round.
"temporary cavity is king"
I have never stated this.what I'll argue and dispute is when I'm told temporary cavity does not happen and can not matter or can not do damage below 600 m/s or 2000 fps.because this is male bovine fecal matter.
I have seen a bullet at ~1250 fps or <400 m/s do enough damage to lung tissue to cause death without entering the chest cavity.
"sufficient penatration is king" but temporary cavity matters otherwise everybody would use FMJ and a .45 would be a signifigantly better stopper than a .357, and since they have co-existed for 72 years and we still have many members who disagree as to which is better.

uncowboy
September 17, 2007, 09:14 AM
The temp cavity can not be relied on as all will act differently. That is why the crushing is the PERMINATE dammage and all that you CAN rely on.

FerFAL
September 17, 2007, 09:23 AM
Notice that 357 magnum, 357 SIG, 38+P and 9mm+P, they all have better stopping power with fast and light, rather than heavy and slow, basically because of the temporary cavity they create. The linked pic is a 44 magnum, the cavity had enough energy to brake the wood board below the gelatin block.

FerFAL

Hauptmann
September 17, 2007, 09:49 AM
Notice that 357 magnum, 357 SIG, 38+P and 9mm+P, they all have better stopping power with fast and light, rather than heavy and slow, basically because of the temporary cavity they create. The linked pic is a 44 magnum, the cavity had enough energy to brake the wood board below the gelatin block.

FerFAL

http://www.firearmstactical.com/tactical.htm

http://www.firearmstactical.com/pdf/fbi-hwfe.pdf

http://www.firearmstactical.com/afte.htm

......didn't you get the memo?

Obiwan
September 17, 2007, 01:10 PM
Sigh....

Thanks Haupt

None are so blind as those that will not listen

Or something like that

There is plenty of good data out there....that has much more backing it up than "I just know this is true"

mavracer
September 17, 2007, 01:24 PM
Noe are so blind as those that will not listen
that street runs both ways
There is plenty of good data out there....that has much more backing it up than "I just know this is true"http://www.ballisticstestinggroup.org


reposted again " it can ,does, and will happen.
I have seen a bullet at ~1250 fps or <400 m/s do enough damage to lung tissue to cause death without entering the chest cavity.

Cosmoline
September 17, 2007, 01:39 PM
Notice that 357 magnum, 357 SIG, 38+P and 9mm+P, they all have better stopping power with fast and light, rather than heavy and slow, basically because of the temporary cavity they create.

That's never been proven. My theory is it's a sales pitch for selling ammo that uses less of the most expensive part of the cartridge--the bullet. I've never seen any evidence that among standard handgun rounds (.32 ACP to .357 range) the faster, lighter rounds have more kiling power or do more damage than the heavier, slower rounds. ALL of the rounds are slow from that range of cartridges. And none of them have the velocity to generate a TC of sufficient magnitude to do real damage on a reliable basis. You'd have to move up to a .44 Mag or load a .357 with slow powder and fire it from a carbine before you start to see that kind of TC.

Personally, I started loading slower and heavier with handguns when I encountered a case of a large man being shot in the belly with the .357 Sig, a round made fast and light by design. The bullet skirted his fat layer without doing anything but shaving some pounds off and making some puncture wounds in his skin. For handguns I'd rather use a bullet with enough sectional density to punch all the way through a human torso leaving two holes and a path for blood to come out both from the central organs.
]

moxie
September 17, 2007, 02:31 PM
"PERMINATE dammage" rocks!

Obiwan
September 17, 2007, 04:37 PM
Mavracer

temp cavity exists.....but is relatively unimportant

If you saw the damage, then it was permanent cavity...not temporary..unless you were taking an MRI of the victim at the time you could not and did not see temp cavity

Handguns are pitiful popguns....there is not enough energy present to do any real damage by stretching tissue

Holes that bleed or CNS damage...that is what incapacitates and/or kills

FMJ penetrates further but makes smaller (dia ) holes for a given caliber

Some hyper velocity HP's open up very big but do not penetrate enough to disrupt enough tissue to matter

Someone can die from fright but that doesn't make the loudest firearm the most deadly :-)

DiN_BLiX
September 17, 2007, 06:20 PM
I think about it like this, I rather throw a brick at someone, than shoot them with a red rider BB gun. Bigger and slower wins, its NOT a race.

mavracer
September 17, 2007, 06:21 PM
If you saw the damage, then it was permanent cavity...not temporary..unless you were taking an MRI of the victim at the time you could not and did not see temp cavity.
no hole in chest cavity,bullet did not enter, massave contusion to lungs animal died from lungs bleeding.

mavracer
September 17, 2007, 06:29 PM
I think about it like this, I rather throw a brick at someone, than shoot them with a red rider BB gun. Bigger and slower wins, its NOT a race.
great logic, so you carry a brick not a .45,NOT.

Vern Humphrey
September 17, 2007, 06:30 PM
no hole in chest cavity,bullet did not enter, massave contusion to lungs animal died from lungs bleeding.
What cartridge?

Obiwan
September 17, 2007, 06:59 PM
a massive bruise:confused:

So the bullet bounced off?

Bleeding is what kills almost everything

Hauptmann
September 17, 2007, 07:12 PM
Courtney doesn't improve his credibility by using Marshall and Sanow data or referencing the Strasbourg Goat Tests. Marshall and Sanow were proved to be very selective in the numbers that they used for their one shot stops and even used unconfirmed "war stories" instead of actual shooting reports. In the late 90s and early 2000s Ed Sanow kept attacking the skeptics of the firearms community for doubting and questioning his work and only made himself look worse. The ballistics experts presented a sound and factual critique of him and he didn't like it. As far as the goat tests go, there is no record of such a test ever taking place. M&S reference it often as one of their foundation principles and they can't even provide documentation to even HINT that such a test took place.

The rest of Courtney's work looks interesting, but I don't buy it yet. His calculations for BPW are performed in a non interupting media of gel and uses a lot of assumptions of how such a wave will behave in the human body with fat, muscle, ribs,....etc. Most loads disipate so much energy in the outer fat layer that using a low mass expanding projectile runs the risk of shallow penetration. You still have muscle, cartilage, ribs, and finally the internals to get through.

If you want to refer to it as the "Fackler" philosophy, I am more inclined to stick to his work. I can list over a dozen ballistics experts with published works to back up their credentials from the "Fackler" philosophy and an additional dozen other experts that promote this research. Kudos for Courtney for putting all his efforts into this area, but at this time I don't think he has many experts in the field convinced. I think he is pushing for a desired result which is both good and bad for research. When you are focued on a desired outcome, you can overlook the obvious in your quest for a better mouse trap.

mavracer
September 17, 2007, 07:27 PM
What cartridge?
handgun 1250 fps,but that does not matter it was not the hole that killed it was damage from the temporary cavity.

mavracer
September 17, 2007, 07:39 PM
So the bullet bounced off?
the bullet entered left side went between ribs through back muscle between either t6 and t7 or t7 and t8 vertabre below spinal cord through the back muscle and stopped under hide on right side.the bullet never entered the chest cavity it did not sever spinal cord(apparently it damaged it the animal dropped in its tracks without the use of hind legs) .the way the animal dropped I could not finish it (log in my way)by the time we got back around and crossed creek 35-45 seconds.animal had expired from lung damage.

RyanM
September 17, 2007, 08:06 PM
And this was what size of an animal? People have hunted bunnies and squirrels with thrown rocks and sticks for millenia. Even today, people who bowhunt tree squirrels will usually use blunt tipped arrows, so they don't have to climb up and get the arrow, and so that a miss that keeps going is much less of a hazard to people.

In any case, for humans and human-sized animals, you need about 800 to 1,000 ft-lbs energy before temporary cavity becomes much of a factor. It can be a factor below that, but you usually end up sacrificing other, more crucial performance (usually penetration) to gain temporary cavity effect. Below 800 ft-lbs, energy is practically irrelevant; penetration and permanent cavity are king.

Hauptmann
September 17, 2007, 08:08 PM
handgun 1250 fps,but that does not matter it was not the hole that killed it was damage from the temporary cavity.

Actually, it is rather important. What was the bullet constuction? Did you recover the bullet?......what was its condition? During cleaning, did you look for broken bone fragments that may have penetrated the lungs?.....or fragments from the bullet itself? The combination of a pneumothorax and the stress of an epinephrine dump will suffocate just about anything. Did you notice physical trauma to the lung sacks and if you did, can you be sure that you did not cause it during cleaning?

Mystery kills happen on occassion with me all the time. It's rare, but I have been able to explain them after I've opened them up most of the time. Bone fragments, bullet fragments, and nerve plexus/spindle damage. Nerve spindles are VERY difficult to see and you will often have to drain body fluids to even notice them. They control intercostal muscle movement which facilitates rib cage expansion for adequate breathing, or called adequate tidal volume. Without that assistance in breathing the diaphragm cannot work hard enough to achieve adequate tidal volume for life especially in a prone position. You can read about arrest subjects suffocating and dieing because they were laying prone and were unable to work their lungs efficiently enough for life.

Lots of variables at the cellular level that you can't explain with a field cleaning......

Vern Humphrey
September 17, 2007, 08:12 PM
the bullet entered left side went between ribs through back muscle between either t6 and t7 or t7 and t8 vertabre below spinal cord through the back muscle and stopped under hide on right side.the bullet never entered the chest cavity it did not sever spinal cord(apparently it damaged it the animal dropped in its tracks without the use of hind legs) .the way the animal dropped I could not finish it (log in my way)by the time we got back around and crossed creek 35-45 seconds.animal had expired from lung damage.
Oddly enough, when I was a wee bouchal boy, I killed a deer with an identical shot from a .22. The damage to the spine was not evident (and would not have been without a necropsy). The animal bled out.

It was killed by the hole -- which happened to be in just the right place.

mavracer
September 17, 2007, 08:26 PM
And this was what size of an animal?
250 lb boar or roughly human size.
What was the bullet constuction? Did you recover the bullet?......what was its condition?
Lots of variables at the cellular level that you can't explain with a field cleaning......

(and would not have been without a necropsy)
yes bullet was recovered.intact had just a little flatening of the exposed lead(sierra JSP),no fragment,no bone fragment,no perferation in the chest cavityand when you clean game with veteriniarians it turns into necropsy.
Oddly enough, when I was a wee bouchal boy, I killed a deer with an identical shot from a .22. The damage to the spine was not evident (and would not have been without a necropsy). The animal bled out.
it would have been gangreen or infection on my animal there was little bleeding from the hole.if you had shot this animal with a arrow in the same location,while paralized, it could have probably lived.

Vern Humphrey
September 17, 2007, 08:29 PM
As I said, I once made the exact same shot with a .22 rifle. The animal went down on his hind legs and bled out.

mavracer
September 17, 2007, 08:55 PM
As I said, I once made the exact same shot with a .22 rifle. The animal went down on his hind legs and bled out.
as I tried to explain, must not have been the same placement as my boar would have if not survived have lived for many hours.
I don't want the BG to bleed out three days later after he killed me and took my car and my keys to my house and killed my family.I'm not condoning one shot stops, mearly that I believe when I'm carrying my .357,10mm or my .45 with its 230 doubletaps,that 2 to the body and I won't be as likely to have to put 1 in the head as I would with the .38 or .32.

Vern Humphrey
September 17, 2007, 09:10 PM
as I tried to explain, must not have been the same placement as my boar would have if not survived have lived for many hours.
With a deer, when the rear legs are paralyzed, the animal is doomed. There is a large blood vessel running just under the spine -- it would be hard to damage the spine from below and not nick this vessel.

I don't want the BG to bleed out three days later after he killed me and took my car and my keys to my house and killed my family.I'm not condoning one shot stops, mearly that I believe when I'm carrying my .357,10mm or my .45 with its 230 doubletaps,that 2 to the body and I won't be as likely to have to put 1 in the head as I would with the .38 or .32.
Killing and stopping are two different things.

phaed
September 17, 2007, 09:18 PM
From a high powered rifle, YES. Vis:

http://www.barnesbullets.com/videos/..._6fps_logo.wmv

From a slow speed handgun, not so much.

that's a very cool video. watch the hp flatten out.

mavracer
September 17, 2007, 09:35 PM
With a deer, when the rear legs are paralyzed, the animal is doomed. There is a large blood vessel running just under the spine -- it would be hard to damage the spine from below and not nick this vessel.
exactly it took more energy.

DiN_BLiX
September 17, 2007, 10:02 PM
great logic, so you carry a brick not a .45,NOT.

now thats just silly.

Cosmoline
September 17, 2007, 10:16 PM
handgun 1250 fps

What cartridge, what weight of bullet, what platform?

DiN_BLiX
September 17, 2007, 10:59 PM
This thread is lost.

mavracer
September 17, 2007, 11:22 PM
What cartridge, what weight of bullet, what platform?

From a slow speed handgun,
why would platform matter 1250 fps is the same no matter revolver, auto,glock,1911. you say it only happens at rifle velocity. I have continued to say only that it happens at handgun velocitys.Does it matter, I don't know.will it make a difference,I will say positivly maybe.IMHO it starts to happen with relative regularity at the upper end of service calibers.ie I have a 10mm load 135 nosler at 1550 fps(it almost duplicates doubletaps load) the only time it doesn't do 12" is in bare gelatin and cloths(it does 11") it passes wallbord,glass and the other FBI criteria.in bare gel its explosive in Mike Mcnett's words "frag nasty".this is is a 720+ ft.lb. "energy dump" that I'd stake my life on in a heart beat.Of course I usually stake my life on much less energy and my ability to shoot.

Hauptmann
September 18, 2007, 12:23 AM
why would platform matter 1250 fps is the same no matter revolver, auto,glock,1911. you say it only happens at rifle velocity. I have continued to say only that it happens at handgun velocitys.Does it matter, I don't know.will it make a difference,I will say positivly maybe.IMHO it starts to happen with relative regularity at the upper end of service calibers.ie I have a 10mm load 135 nosler at 1550 fps(it almost duplicates doubletaps load) the only time it doesn't do 12" is in bare gelatin and cloths(it does 11") it passes wallbord,glass and the other FBI criteria.in bare gel its explosive in Mike Mcnett's words "frag nasty".this is is a 720+ ft.lb. "energy dump" that I'd stake my life on in a heart beat.Of course I usually stake my life on much less energy and my ability to shoot.

I used to be a high velocity groupe. Wouldn't carry anything less than a .357mag. It took discipline, patience, and an open mind to analyze the research done by those that have more experience than me and even look deeper beyond that. I even invested in slow and heavy rifle calibers such as the .45-.70 instead of my Weatherbys to hunt elk. What I discovered on my own was that the caliber that created that largest wound channel or tissue damage through fragmentation seemed to work best on big game. In fact, the .45-.70 with expansion loads seemed to be the best overall elk rifle I've ever used. My .375 H&H mag offered similar performance because the physical wounding capability was similar.

In regard to cracking gel which carries over to the surround support structures, such a phenomenon has never been demonstrated in living tissue.

You are being asked a lot of questions because you are so defensive in answering them. This raises a lot of suspicion because if such a hunting incident occured there is no reason to not disclose what ammo you used, what caliber, and what platform. Since you still haven't answered those three questions from multiple posts in this thread I'm not sure I really believe you.

Also, you talk about how your hand loads perform in gel and other substances. Did you use 10% ballistic gel calibrated at FBI standards? Correct density, elasticity, block size, block securing, and mandatory temperature regulation? If not, your tests are invalid. Without adhering to the FBI protocals you will not get the same results that would with the standardized test. By the way, McNett has never posted proof that he uses FBI protocals. In fact, he always dances around the question and never shows his customers any evidence that he uses properly made FBI ballistic gel. I'm willing to bet that his penetration levels are actually more shallow than he advertises. His velocities stress the limits of the Gold Dot bullet construction and with the higher impact energy you get more rapid expansion that what the bullet was designed for. The result is faster deployment of the parachute which we call the hollow point with good expansion, but more shallow penetration. Speer did this experimentation in their factory and got these results when they cranked up velocity.

mrmeval
September 18, 2007, 02:36 AM
Heh, figure up the weight of a truck in grains then figure out it's velocity in FPS.
For instance a 50,000 pound truck at 60MPH would be how much energy?

mavracer
September 18, 2007, 08:47 AM
In regard to cracking gel which carries over to the surround support structures, such a phenomenon has never been demonstrated in living tissue.
yes it has your in denial.
You are being asked a lot of questions because you are so defensive in answering them. This raises a lot of suspicion because if such a hunting incident occured there is no reason to not disclose what ammo you used, what caliber, and what platform. Since you still haven't answered those three questions from multiple posts in this thread I'm not sure I really believe you.
I have been hesatant to say its a 300 grn 44. because now you will say oh that makes a difference. when I originally posted it to dispute the 600 m/s floor for cavatational damage.yes I know you guys change your tune and say oh its not velocity its energy.I also dispute Vern its the hole and only the hole that kills.because the hole in my pig was in back muscle only it did not hit the spine or any major arteries nore did it enter the chest cavity the damage was done by energy transfer from bullet to muscle to lung.
Also, you talk about how your hand loads perform in gel and other substances. Did you use 10% ballistic gel calibrated at FBI standards?
sorry know you wan't to muddy the water arguing details my kids do the same thing. I'll play just for you.
MY HAND LOADS DUPLICATE A FACTORY LOAD WHICH WAS TESTED IN 10% BALLISTIC GELATIN

mavracer
September 18, 2007, 08:51 AM
For instance a 50,000 pound truck at 60MPH would be how much energy?
6,019,900 ft.lb.

ranger335v
September 18, 2007, 09:03 AM
BLiX, #22: "... rather throw a brick at someone, than shoot them with a red rider BB gun. Bigger and slower wins, its NOT a race."

Understand what you are saying and agree in principle. But, it's wrong as stated.

Elmer Keith wouldn't directly agree that there is any virtue at all in "slow", he too wanted as much speed as possible. Elmer, and others, simply recognised that BIG HOLES were, on average, more effective than small ones. So, he did every thing he could to acclerate the big bore bullets he loved.

Big and fast is always much more effective than small and fast, that's why even mild rifles are more effective than hot handguns. If you have to sacrifice some speed to use bigger projectiles, so be it. A boulder need not travel fast to flatten anyone but it's hard to hit from much distance with a heavy boulder. Unless it's straight down! :)

Michael Courtney
September 19, 2007, 04:32 PM
no
the round must have at least a velocity of 600m/s before cavitation has a consistant meaningful effect.there's almost always a discernable effect there is damage larger than the expanded round.

In lung tissue of deer, we have consistently seen a wound larger than the recovered diameter of the bullet for bullets transferring at least 500 ft-lbs of energy per 12" of penetration. We really believe that the local rate of energy loss (ft-lbs per foot of penetration) rather than velocity is the determining factor in effects beyond direct crush.

Michael Courtney

Soybomb
September 20, 2007, 01:16 AM
By the way, McNett has never posted proof that he uses FBI protocals. In fact, he always dances around the question and never shows his customers any evidence that he uses properly made FBI ballistic gel.
Do you have a link to this?


Originally posted by MCNETT
We conduct all of our ballistic testing using the FBI tests using 4 layers of denim and two of light cotton over a properly calibrated block of 10% gelatin.
-Mike

Speer did this experimentation in their factory and got these results when they cranked up velocity.
Link to documentation? I've read where people have emailed speer and asked if there was a problem driving the bullets at these speeds and they got the just fine answer back.

with the higher impact energy you get more rapid expansion


Dr. Roberts:
Unfortunately, there is a significant amount of misinformation on rate of expansion; a simple test is to shoot through a thin 2 or 3 inch thick piece of gelatin and then capture the bullets in a recovery box that prevents further bullet deformation. The vast majority of well designed handgun service caliber JHP’s will be fully expanded by the first couple of inches of travel.

Do you have some evidence of these rounds expanding at unusual rates showing a detrimental effect? If it fragments or the edges fold back we should see it in gel.

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