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Old September 25, 2012, 11:38 PM   #76
sigcurious
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Only moving projectiles can cause damage
Some levity for an otherwise serious conversation...The person could be moving at 1000fps and the projectile could be stationary and do damage.
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Old September 26, 2012, 12:05 AM   #77
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Originally Posted by JohnKSa
...it is not possible to say that kinetic energy does not cause damage since...
Perhaps something of an oversimplification, but as stated in In Defense of Self and Others... (Patrick, Urey W. and Hall, John C., Carolina Academic Press, 2010, pp. 95-96, italicized emphasis in original, bold emphasis added):
Quote:
Kinetic energy does not wound. Temporary cavity does not wound. The much-discussed "shock" of bullet impact is a fable....The critical element in wounding effectiveness is penetration. The bullet must pass through the large blood-bearing organs and be of sufficient diameter to promote rapid bleeding....Given durable and reliable penetration, the only way to increase bullet effectiveness is to increase the severity of the wound by increasing the size of the hole made by the bullet....
And it is more precisely stated by Duncan McPherson (as quoted by 481 in post 67):
Quote:
...Any attempt to derive the effect of bullet impact in tissue using energy relationships is ill advised and wrong because the problem cannot be analyzed that way...
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Old September 26, 2012, 12:06 AM   #78
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...The person could be moving at 1000fps
Right now, I'm either stationary, moving at about 1300fps, or 95,000fps or 700,000fps. It all depends on which reference plane I choose.
Quote:
Perhaps something of an oversimplification, but as stated in In Defense of Self and Others...
I've read Urey's paper and the quote is reproduced correctly. The problem is that Urey is wrong. He was on the right track, but he got carried away and overstated his case.

It's one thing to say that kinetic energy/temporary cavity are not a reliable wounding mechanisms in handgun terminal ballistics, it's another entirely to take the next step and say that they do not wound. The former is debatable and dependent upon the energy levels and types of tissue involved. The latter is demonstrably false. Temporary cavity, which is accepted to be directly related to energy, CAN wound, it just hasn't been shown to wound reliably at the energy levels commonly encountered in self-defense handguns. At typical handgun levels, to date, it has only been demonstrated that it can cause significant wounding if inelastic tissues are involved, but in those cases it can not only cause wounding, it can cause catastrophic wounding.

As far as his statement that kinetic energy does not wound, that's simply nonsensical from a scientific standpoint. Kinetic energy is the potential of a moving projectile to do work. Damage to the target medium is, at least to some extent, related to the work done on the target medium by the projectile and therefore is, in some way (which may be very complex and difficult to determine) related to the kinetic energy.

I don't have enough context from MacPherson's quote to know exactly what point he was trying to make. It is certainly true, as has been stated by others, that attempting to fully analyze the terminal ballistics problem using only kinetic energy (or any other single parameter) is impossible due to the complexity of the problem, however, that is not sufficient justification to completely dismiss kinetic energy as a factor in the overall problem.

Just to be clear, I'm not claiming that kinetic energy is the most important factor in ballistics--not by any means. I'm just saying that the fact that it's not the most important factor, or the fact that it can't/doesn't tell the whole story doesn't change the fact that it is certainly part of understanding terminal ballistics and that it provides useful insight into the problem.
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Old September 26, 2012, 12:18 AM   #79
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LOL well played sir!
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Old September 26, 2012, 01:03 AM   #80
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Originally Posted by JohnKSa
...As far as his statement that kinetic energy does not wound, that's simply nonsensical from a scientific standpoint....
But I think that the point he's trying to make is that energy as a indicator of a defensive handgun cartridge's effectiveness is not helpful and even counter productive. He is, in essence, responding to what amounts to an obsession with energy, even at typical handgun velocities.

We so often see the passionate claims that cartridge A is superior to cartridge B because it has 500 ft-lbs of energy at the muzzle compared with the meager 450 ft-lbs of cartridge B.

To be sure, a projectile that is moving had kinetic energy. And a bullet to effectively penetrate must have some minimum level of kinetic energy. But factors such as sectional density of the bullet, momentum and diameter/expansion of the the bullet and thus the permanent wound cavity are more useful and relevant to trying to predict terminal performance, at least at typical handgun velocities.
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Old September 26, 2012, 01:35 AM   #81
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But "energy dump" is meaningless.
Not true.

Take a ping pong paddle and a ping pong ball and hit a guy in the head with the hardest serve you can manage.

Then take a golf club (the driver) and a golf ball and hit that same guy in the head with the best drive you can manage.

Note the different effects on the target.

Neither the ping pong ball nor the golf ball will cause a permanent wound channel.
And neither one will give any penetration.
And neither one will destroy tissue in its path.

But the golf ball could kill the guy.


Why?

The golf ball delivers much much greater energy to the guy's head.


Energy delivered to the target matters.



If you don't believe me, you provide the test head and I'll provide the ping pong ball and the golf ball.
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Old September 26, 2012, 01:43 AM   #82
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Originally Posted by peacefulgary
...The golf ball delivers much much greater energy to the guy's head....
There's a significant difference between the physiology of injury from blunt force trauma and injury from a penetrating wound.
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Old September 26, 2012, 03:44 AM   #83
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But I think that the point he's trying to make is that energy as a indicator of a defensive handgun cartridge's effectiveness is not helpful and even counter productive. He is, in essence, responding to what amounts to an obsession with energy, even at typical handgun velocities.
Perhaps. In any event, he swings too far the opposite direction.

Kinetic energy is helpful in understanding terminal ballistics and handgun cartridge effectiveness. It does not, by any means, tell the entire story, and one can certainly be led astray by becoming obsessed with it or by giving it too much consideration when comparing cartridges. However, science does not allow us to discard it, nor is it wise to discount it too much given the obvious correlation between energy, work and damage.
Quote:
But factors such as sectional density of the bullet, momentum and diameter/expansion of the the bullet and thus the permanent wound cavity are more useful and relevant to trying to predict terminal performance, at least at typical handgun velocities.
The complexities and vagaries of dealing with energy and temporary wound cavities have led some to focus exclusively on other parameters because they allow a more consistent and simpler analysis. However, of necessity, leaving out a factor as basic as kinetic energy leaves their analysis wanting in at least some respects and leads to conclusions that, in some circumstances, can be just as inaccurate and just as unnecessarily limited as those which are generated by people who focus exclusively on energy as a measure of terminal ballistics. Many of the obviously unsupportable statements about discounting temporary cavity and kinetic energy originate from those who have so much invested in these simpler analyses that provide more consistent, though perhaps less accurate, results because they perceive this tactic to be the only way to maintain the credibility of their conclusions.

One very simple example--the list provided as being more useful than energy includes expansion. However, expansion is more closely related to energy than any of the other listed parameters since it is evidence of work done on the projectile and that work is a function of impact energy. Ultimately, energy plays at least some part in nearly every aspect of terminal ballistics--an important part in some respects and under certain circumstances and perhaps a trivial part in other respects and under another set of circumstances.

A list of the "ABCs" of terminal ballistics is just as incomplete without kinetic energy as it would be if one excluded momentum or velocity, and it's not possible to fully understand the topic without understanding how it's affected by kinetic energy. I'm not saying anyone does fully understand the topic--I'm just saying that kinetic energy is one of the basic building blocks of terminal ballistics and any house built without it is incomplete.
Quote:
There's a significant difference between the physiology of injury from blunt force trauma and injury from a penetrating wound.
It's just as true to say that there's a significant difference between the physiology of a penetrating wound and a wound caused by a high velocity projectile.

The reason both statements are true is that a wound from a high velocity projectile incorporates aspects of both penetrating wounds and blunt force trauma.

In fact, temporary wound cavity is an excellent analog for blunt force trauma. If one is hit in an area containing or composed of brittle or inelastic tissue, it can be catastrophic. If one is hit in an area that is largely made up of elastic tissue, there may be little effect other than pain.

If one completely ignores kinetic energy and temporary cavity, one ignores one of the two main components of high velocity projectile injuries. It's certainly true that the circumstances of a particular situation may dramatically emphasize one of the two aspects over the other, but neither one is ever completely absent, except, perhaps, when effective body armor is involved and there is no penetration.
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Old September 26, 2012, 04:19 AM   #84
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#8 post

[QUOTEReliability, then accuracy, then adequate penetration, then shootability, and last expansion as I see it.

I like Federal HST standard pressure at the heaviest weight per caliber: 230 for .45, 180 for .40, and 147 for 9mm. All are subsonic, but all move at good velocity (850 .45, 1000 for .40, 990ish for 9mm). All get around 12-12.5" in gelatin, do well (for caliber) with barriers, and offer reliable expansion. ][/QUOTE]

Good post, short and sweet.

The reason I love the 9mm, rapid shots are possible, less recoil, you get a bunch of them! Glock19 has 16 ready to go.
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Old September 26, 2012, 05:34 AM   #85
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Quote:
The golf ball delivers much much greater energy to the guy's head.


Energy delivered to the target matters.



If you don't believe me, you provide the test head and I'll provide the ping pong ball and the golf ball.
I'll step up and take you up on that offer!
Provided one teeny tiny litte detail....

I get to call the range...say,,200 yards?

It's all relative & it's all the different pieces of the ballistic puzzle.
Depsite having a lot of "muzzle energy" a foot or two away from the T.
Downrange, that golf ball hasn't got enough left to resist being thrown off course by a blade of grass.

OTOH - no way no how would I stand in front of a ping pong ball launched from some device that could toss it 6 or 7 thousand fps.

Again - I keep going back to what I concluded...
Velocity is the more critical figure I'd want to know. The energy will either be there or it won't.

Velocity is also a much better indicator of how far downrange I can go & how flat the round will shoot.
Energy figures don't really tell me that.
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Old September 26, 2012, 06:50 AM   #86
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Quote:
Originally Posted by MLeake
AB, I think what 481 was saying that while energy goes up in direct proportion with an increase in mass, it goes up as the square of a velocity increase.

Twice the mass, twice the energy. Twice the velocity, four times the energy. So, if energy is the overriding concern, the answer will typically be to increase velocity, rather than mass.

Momentum goes up in linear fashion with both mass and energy.
If that's what he was saying, he should have said it. However ...

The question in the original post did not ask if we consider velocity or bullet weight to be more important, it asked if we consider velocity or muzzle energy to be more important. Those two come from opposite sides of the equation. Muzzle energy, as has by now been thoroughly explored in this thread, is derived from the bullet weight and the square of the velocity. Those are the two variables, and the muzzle energy is the result -- the product of the equation.

So the original question really asked if we are more concerned with one of the two input factors, or with the output. I am concerned with the output -- especially if one of the two input variables is unknown and is not part of the discussion.
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Old September 26, 2012, 08:52 AM   #87
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AB, I counter thus:

Velocity's importance could be based not only on going fast enough (to yield effective energy, and desired range and flatness of trajectory), but also on not going too fast.

Most firearms have a sweet spot in velocity for accuracy.

Most projectiles have a velocity range below which, they will not expand, and above which, they fragment - potentially preventing penetration. (Alliteration free of charge.)

So one could argue velocity is more important with regard to finding the ideal velocity for the particular firearm and bullet combo.

That would be a completely separate argument than velocity, solely with regard to energy level.
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Old September 26, 2012, 08:56 AM   #88
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Quote:
Originally Posted by Aguila Blanca:
If that's what he was saying, he should have said it. However ...
Well, at least MLeake got it. He is either very perceptive or I need to double up again on the layers of aluminum foil wrapped around my head so he can't read my mind- my bet is on the former.

Quote:
Originally Posted by Aguila Blanca:
The question in the original post did not ask if we consider velocity or bullet weight to be more important, it asked if we consider velocity or muzzle energy to be more important. Those two come from opposite sides of the equation. Muzzle energy, as has by now been thoroughly explored in this thread, is derived from the bullet weight and the square of the velocity. Those are the two variables, and the muzzle energy is the result -- the product of the equation.

So the original question really asked if we are more concerned with one of the two input factors, or with the output. I am concerned with the output -- especially if one of the two input variables is unknown and is not part of the discussion.
I'll be much more concise here for your sake- the point is that whether you consider kinetic energy or momentum to the determinant factor of ballistic performance, you cannot separate mass and velocity from one another in those quantities (kinetic energy and momentum) since they are both dependent upon both variables- mass and velocity.

For that reason, the question asked by the OP, "In a defensive rd for a handgun which is more important to consider....muzzle velocity or muzzle energy?" is meaningless- even nonsensical- since velocity is a component of kinetic energy and momentum.

As a result, the OP's question essentially amounts to asking, "In a defensive rd for a handgun which is more important to consider....muzzle energy or muzzle energy?"

It seems that he had his answer before anyone posted.
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Old September 26, 2012, 09:03 AM   #89
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Originally Posted by MLeake:
(Alliteration free of charge.)


Nice...
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Old September 26, 2012, 09:10 AM   #90
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.357 Mag or .44 Mag FMJ's always penetrate and most of the time, leave a hole all the way through. To me the projectile size and type makes more difference than velocity.
The only high velocity cartriges I really care about are varmint rounds because you need velocity for long range shots.
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Old September 26, 2012, 01:13 PM   #91
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From John:

Quote:
Quote:
"Energy does not do the damage either in handguns or rifles, the bullet does the damage in both."

Without kinetic energy, the bullet does not move and therefore it does no damage. Only moving projectiles can cause damage, and therefore it's not possible to dismiss kinetic energy as a factor in the damage caused by moving projectiles.
You seem to have deliberately obscured the point through selective quotations, that or you attribute mystical properties to energy.

The sentence you quote from me in no way dismissed kinetic energy. But it seems you missed that and it may be because you tend to treat kinetic energy as a force distinct and apart from the moving bullet. Odd because you correctly say..."only moving projectiles can cause damage" which is correct and a point I made. It is the bullet that does the damage. The amount of kinetic energy that the bullet possesses is a factor in how much damage.

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Old September 26, 2012, 01:28 PM   #92
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The temporary stretch cavity is a factor in wounding. Nerves, blood vessels, arteries, muscle tissue etc. are stretched and torn to one degree or another (based on a variety of factors) which do effect the severity of the wound.

Fackler and others bent the stick too far during the course of their debates, when they said the so called temporary cavity was not a factor. They were correct in insisting that the only thing that could be counted on though was the direct path the bullet took.

Both the mass of the bullet and it's velocity and energy are factors.

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Old September 26, 2012, 02:04 PM   #93
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Quote:
Originally Posted by tipoc
...the mass of the bullet and it's velocity and energy are factors...
These aren't three factors. They're just two. With the mass and velocity you also know (can calculate) kinetic energy. Mass and velocity also tell you momentum.
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Old September 26, 2012, 02:37 PM   #94
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Perhaps. In any event, he swings too far the opposite direction.
Quote:
Fackler and others bent the stick too far during the course of their debates, when they said the so called temporary cavity was not a factor. They were correct in insisting that the only thing that could be counted on though was the direct path the bullet took.

Both are correct, which is why Fackler was ultimately run off from the FBI and the IWBA is now only a memory. They drank their own cool aid and manipulated data to suit their agenda, Dr Wolberg at San Diego was one of the obvious ones with the paper on the subsonic 147 grain 9mm.

We hear so much about it because they are "doctors" and have published papers all over the errornet.
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Old September 26, 2012, 04:25 PM   #95
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Originally Posted by Nanuk:
They drank their own cool aid and manipulated data to suit their agenda, Dr Wolberg at San Diego was one of the obvious ones with the paper on the subsonic 147 grain 9mm.
Still peddling the same worn-out disinformation, huh?

Wolberg's research paper is valid, here's why-

It is common and accepted practice for researchers to select the parametric and data constraints for their case studies. If this were viewed as reason to discredit his or anyone else's research and findings, then every case study research article that has ever been written and its findings would have to be thrown out. In fact, parametric and constraint selection is a sound practice within scientific research projects and to attempt to portray it as some sort of dishonesty is an act of intellectual dishonesty itself. So long as it is done honestly and openly (as evidenced by Wolberg's explanations of the constraints of his data selection on the first page of the article cited above) and the reasons for such constraint can be shown to be valid, then it is a valid practice.

Wolberg does this on the first page (marked as page 10) of the article stating:

Quote:
from pg. 10- fifth paragraph: "It should be noted that all head wounds, and bone hits were eliminated; this study deals only with shots that penetrated soft-tissue of the torso and did not hit bone."
In case you haven't read the paper, Wolberg was attempting to establish a correlation for the behavior of expanding projectiles in soft tissue and calibrated ordnance gelatin which is a soft tissue analog. Therefore, it was necessary to eliminate the data that included hits to bony tissue and the cranium since the correlative relationship being investigated is one involving projectile behavior in soft tissue and a soft tissue analog- not that of calibrated ordnance gelatin to bony tissues.

Wolberg states (also on the article's first page) that only shots that remained within the bodies of those being autopsied were considered for this correlative study:

Quote:
from pg. 10- second paragraph: "Only shots into the torso that remained in the body for their entire penetration depth were included in the study."
This constraint is justifiable also, because in order to compare total penetration depths in both mediums the entire wound track must be captured so that it can be measured. Projectiles that exited the bodies of those in the available test population cannot be used because the projectile's wound track was not captured in its entirety. Wolberg's disclaimer states this clearly and in plain language on the first page (10) of his research article and the language quoted above is taken directly from his article. That he elected to inform the reader of the constraints that he employed speaks volumes to the man's character.

Portraying Wolberg as being dishonest, when in fact he wasn't, as is demonstrated by the disclaimers described above, is intellectual dishonesty.

Anyone wishing to read Wolberg's article for themselves-

http://ammo.ar15.com/project/Fackler...hester_9mm.pdf

-may do so and confirm for themselves the text that I have specifically quoted from the article and that it is presented clearly and plainly for anyone to see.
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Old September 26, 2012, 07:14 PM   #96
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As I said before... Energy transfer from handguns does not cause enough cavitation to create permanent damage in tissue. This cavitation is expressed as the "temprorary" wound cavity. HP rounds do increase energy transfer, and cause a little more cavitation, but not significant amounts. The permanent wound channel is the same size or a little larger than the bullet as it passes through. Expanded HP do increase the size of this permanent wound channel.

This lack of cavitation damage excludes the more dense and inelastic tissues... but those tend to be vital organ tissue like the heart, liver and kidneys... All of which would cause massive bleeding and death when hit directly anyway, the extra damage created is a little less important in this situation. (the heart is of course quickest to death, followed by the liver then kidneys)

What the energy transfer and temporary cavity do... is cause bruising and pain. So higher energy rounds will hurt more, but pain is not a guarantee of stopping the threat.

Now rifle rounds... their higher energy and momentum create much more cavitation... This cavitation is actually more than the elasticity of the tissues can take, and it causes permanent damage. So you get a much larger permanent wound channel... HP increase this effect further... So this is why energy is more effective in rifles.



Handguns can only rely on shot placement and adequate penetration to reach important structures. Momentum and weight aid in penetration.

Handgun rounds all have the momentum to penetrate deep enough, but HP rounds cause energy and momentum loss, which means the rounds may not penetrate deep enough if the HP design causes expansion to quickly.

This is why heavy for caliber rounds penetrate deeper and more consistently... the inherent inertia of the added bullet mass, plus the momentum of the bullet work together to create better penetration depth and consistency.

Higher energy rounds do penetrate more, but without the added mass inertia, the performance of penetration depth is less consistent.

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Old September 26, 2012, 07:29 PM   #97
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Quote:
Neither accuracy nor reliability fall under ballistics.

Initial muzzle velocity is of importance for long range shots. The quicker a bullet gets to its target, the less time gravity and wind have to act on that bullet. Gravity is constant, wind isn't.

Bob Wright

I never said accuracy fell under ballistics. I just said "to me, accuracy trumps 'em both" in reply to the question posed by the OP.

Quote:
In a defensive rd for a handgun which is more important to consider....muzzle velocity or muzzle energy?
Virtually any ammo designed for SD will have appropriate velocity and energy if one hits the BG where it counts. All that velocity and energy produced by magic bullets don't mean a thing if you miss or just wing em. This is why I consider accuracy first. Others opinions may differ. I have no problem with that. I am also in the opinion that when it comes to civilian SD ammo, long range shots don't even come into the picture, much less be of any concern. I mean, at civilian SD ranges, who in their right mind would worry about gravity and wind unless one was throwing a paper airplane at the BG?
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Old September 26, 2012, 09:43 PM   #98
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Quote:
Energy transfer from handguns does not cause enough cavitation to create permanent damage in tissue.
Energy transfer from common service caliber handguns does not cause enough cavitation to reliably create permanent damage in tissue, but a stronger statement can not be justified by the facts.

It is well-documented that it can cause permanent damage to inelastic tissue, and there is also evidence that, under certain circumstances, it can even cause permanent damage to elastic tissue.

This article discusses injuries to arteries caused by temporary stretch. According to the article, these types of injuries can be found in patients with "gunshot wounds inflicted by handgun or rifle".

http://www.ajol.info/index.php/sajs/...le/34334/24724
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Old September 27, 2012, 04:35 PM   #99
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If it isn't reliable... then it can't be relied on nor counted. Would you consider ammo that has a 1% failure rate reliable enough for defense work? Then why credit extra damage that is low reliability...



Internal hemorrhaging in tissue is bruising... its only a serious problem in a open cavity or if its outside the body. Its also not a major issue if the damage is to smaller arteries. At least not with the speed needed in a defense situation.
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Old September 27, 2012, 10:33 PM   #100
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Quote:
Originally Posted by MLeake
Most projectiles have a velocity range below which, they will not expand, and above which, they fragment - potentially preventing penetration. (Alliteration free of charge.)

So one could argue velocity is more important with regard to finding the ideal velocity for the particular firearm and bullet combo.
I think we're getting beyond galoshes here and getting into hip boots territory, but try this: It isn't a bullet's velocity per se that causes expansion, it's the energy driving the bullet into the medium. It's not really possible in the real world, but it could be computer modeled: Suppose you could take two projectiles of the exact same shape and profile -- say, a .45 caliber, 230-grain Golden Saber bullet. One of the two IS a 230-grain Golden Saber bullet. The other doesn't use lead as a core but instead is made of some alloy of Unobtanium, that has zero mass. So projectile number two has the same jacket, the same open nose, the same cavity ... but the "stuff" inside weighs nothing so the total projectile weight is not 230 grains but perhaps 30 grains. (?)

Now accelerate both to the exact same velocity and let each one impact your test medium of choice: ballistic gelatin, wet newsprint, hog carcass, your mother-in-law ... whatever you choose. I respectfully submit that the second projectile -- the one filled with a core made up of weightless Unobtanium -- will not expand nearly as reliably as the standard Golden Saber projectile.

Why? Because it requires energy to expand metal, and both lead and copper are metals. It is hydrostatic pressure of the impacted medium that presses into the cavity to force the bullet to expand, but the impact medium is static. It has no kinetic energy, so where does the energy come from? It comes from the energy -- the momentum -- of the projectile. Yes, it requires velocity, but it also requires mass -- and the question posed at the start of this discussion ignored mass. ALL we were asked about was velocity or energy. Projectile number two in my hypothetical experiment will have FAR less energy than the standard bullet, at the same velocity.

When those are the only two options, the only valid choice is energy.
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