Energy Dump - A Self-Defining Term

I have said (over and over) that what I am talking about applies to normal service rounds. I am not talking about maxed out loads by a company like Buffalo Bore.

I have said (over and over) that what I am talking about applies to normal service rounds. I am not talking about maxed out loads by a company like Buffalo Bore.

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you have said over and over you think either it happens (high power rifle) or there is no damage outside the bullets path(low powered handguns)you admit you don't think you have treated many .357 wounds.I doubt you are told what ammo was used.if your using all the gang related shootings with .22s and .380s you don't have a good data base.accepted service rounds include .357 and 10mm they're very good at what they do because they have more energy than 38s and 9mm.they cause damage outside of the path of the bullet.
In your experiance have you seen a wound identifyed as being from a 125grn .357,I have.I know what bullet load combination do the most damage because I know what I put in the gun,I know what friends and family put in theirs.and as I said before,cleaning game with veternarians turn into autopsys.
it may be safe to assume you don't see the people shot with the better performing rounds, cause they go to the morgue.

I don't believe energy dump (in ft/lbs) has any relation whatsoever to stopping power in handguns, because most service rounds have very low kinetic energy. (usually between 150-600 ft/lbs.)

When it comes to handguns I firmly believe the only thing that matters is penetration and hole size, and anything else is a plus but cannot be counted on or measured on a significant scale. The .44 Magnum and other high powered revolver cartridges are the exception to the rule, and may produce some sort of signifcant effect using kinetic energy.

As a general rule, I don't believe anything that strikes a target under ~1500 ft/lb of energy can use said energy to significantly contribute to wounding factors. Some put the number lower, perhaps around 1000, but I'd put it around 1500, pretty close to a standard 7.62x39mm cartridge.

(I would define kinetic energy as a non-solid, non-molecular force that damages tissue)

The 'research' by Dr Courtney is not relevant to this thread. He and his co-author are suggesting that a 'ballistic pressure wave' can incapacitate a human by remote CNS effects (beyond the range of effect of a temporary cavity).

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Not exactly. Our pressure wave hypothesis states:

Other factors being equal, bullets producing larger pressure waves incapacitate more rapidly than bullets producing smaller pressure waves.

There seems to be considerable evidence that remote CNS effects are real. However, we do not believe that there is sufficient data to exclude other possibilities (increased temporary cavitation, increased prompt damage, "neurogenic shock", "wind knocked out", etc.) for the tendency of incapacitation rates to increase with ballistic pressure wave. The pressure wave hypothesis is really about the bottom line that greater pressure wave increase the incapacitation potential. The fact that one particular mechanism has more documented data in the peer-reviewed literature does not necessarily exclude other possible mechanisms.

HWFE was written a long time ago, and it ignores a number of prior publications in the peer-reviewed literature that do show correlations between energy transfer and tissue damage. There has also been significant later work that also supports the relationship between energy transfer and tissue damage.

The interaction between bullet and tissue and the relevant effects are best parameterized in terms of the retarding force between the bullet and tissue rather than the impact velocity. For non-fragmenting bullets, the average retarding force is accurately estimated by the impact energy divided by the total penetration depth in ballistic gelatin. Tissue damage beyond the tissue directly crushed by the expanded bullet often appears at average retarding forces above 500 lbs (500 ft-lbs of energy transferred in 1 foot of penetration). Since the retarding force is equal to the local rate of the projectile's energy loss in tissue, it is accurate to describe related wounding mechanisms in terms of "energy dump." This retarding force is the dominant parameter in temporary cavitation, prompt damage, and ballistic pressure wave mechanisms.

Relatively few handgun loads produce these levels of retarding force, so this effect is rarely seen by trauma surgeons. However, we have documented it in deer, where we observed a wound channel as wide as 1.5" in the liver and 1.0" in the lungs from a bullet with a recovered diameter of 0.58". The Triton Quik-Shok which splits into three smaller fragments also creates a large region of pulverized tissue in the region between the fragments for the first 5-6" of penetration. These bullets both have impact velocities well below 2000 fps.

See: http://arxiv.org/ftp/physics/papers/0702/0702107.pdf

Michael Courtney

My hypothesis on that would be that cells and tissue are able to aborb a certain amount of energy, and remain viable. After a certain threshold is reached, the cells and tissue die. I don't think the change is gradual... either the cells survive the energy, or they die. Its binary.
I freely admit this is just my opinion, based on taking care of gunshot wound victims. But either there is a large amount of dead tissue around a wound channel (as with a high powered rifle) or there is none (as with most handgun rounds).

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On a cell-by-cell basis, you're right, each cell will eventually live or die. However, from a tissue viewpoint, each cubic mm contains many cells, and the relevant parameter when deciding whether that tissue needs to be debrided is probably the fraction of cells that will ultimately survive (as well as the body's ability to cope with the necrotic cells). Antibiotics probably allows the body to cope with a higher percentage of necrotic cells, thus today's surgeons can debride less tissue than in the pre-antibiotic days.

The practical wound observations that lead a surgeon to debride tissue (or not) are something of a mystery to me. I've read much of the debate in the literature, and the advice to treat the wound rather than the weapon seems very sound. I think there is room for further studies on follow-up of results of minimal debridement. I've seen a lot of wounds in deer, and I've seen a lot of minor hemmorhaging at significant distances from the wound channel. This tissue probably would not need to be debrided, but it is evidence of remote effects.

But the question of incapacitation centers around neural effects and rate of blood loss rather than eventual cell necrosis. Debridement is of peripheral but not direct relevance to the incapacitation question. In animal models, both remote neural effects and significant vascular damage beyond the expanded projectile diameter have been documented for some projectiles near the upper end of energies available in service caliber handguns.

Michael Courtney

Antibiotics don't really minimize the amount of tissue that needs to be debrided. If the tissue is dead, it needs to be debrided, if it is present in any significant amount. If the would becomes infected, it needs antibiotics. Usually prophylactic antibiotics are given for a while after a gunshot wound, but this isn't done to prevent tissue necrosis, but to prevent tissue infection.

Also, generally I will allow a wound to demarcate before undertaking any debridement. If you give the tissue some time, it will be easy to tell whats dead and whats alive. That way you don't end up debriding tissue that might have been injured but not necrotic.

So the long and the short of the argument is this, extra energy CAN help stop an assailant sooner (albeit how much sooner is difficult to measure).

It's up to individual shooters to determine if they want to go with higher energy, higher recoil rounds in the hopes of increasing the probability of a quicker 'stop' (likely through psychological means) or standard service ammunition that allows faster followup shots to increase the probablity of that 'guaranteed' CNS stop.

Antibiotics don't really minimize the amount of tissue that needs to be debrided. If the tissue is dead, it needs to be debrided, if it is present in any significant amount. If the would becomes infected, it needs antibiotics. Usually prophylactic antibiotics are given for a while after a gunshot wound, but this isn't done to prevent tissue necrosis, but to prevent tissue infection.

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You started out saying 2000 fps is where "energy dump" has an effect.I depict an example of great damage from a round at 1250 fps.then your oh well maybe its 1000 ft.lbs. I say I've seen it in the 700-750 ft.lb range.you say well I'm talking normal service rounds.I said as I have before I don't think "energy dump" has much effect below 400 ft.lbs. and now you want to talk about a bullets ability to cause necrosis and infection.
I really don't thing anyone wants to wait on infection or ganggreen to set in.and I don't see the relevance of necrotic tissue as all of this takes several days to have an effect.

I'm searching around for a few journal articles that pertain to this, and will post them when able. This should help fuel the discussion.


Here's an online book about wound ballistics:
http://books.google.com/books?hl=en&lr=&id=jZf1GaXQUvQC&oi=fnd&pg=PR7&dq=bullet+energy&ots=bHfLX3u2_y&sig=jOXB4A-AZ6si5KWhT8CWtSXPsw0#PPA215,M1
It covers handgun wounding effects, rifle wounding effects, and a load of other things. It's somewhat limited for copyright reasons I suppose, but the title and everything is there if you want to find the entire book for more information.

And another:
http://books.google.com/books?hl=en&lr=&id=VbrDbbHAflsC&oi=fnd&pg=RA1-PR15&dq=%22wound+ballistics%22+energy&ots=xjpA92k6Mo&sig=S8gk_bYqaBeEmyL9_6JC1XHov1w#PRA1-PA54,M1
Start at page 54.

And last, an article:
http://arxiv.org/ftp/physics/papers/0701/0701266.pdf

It seems that energy transfer (amount, rate of transfer) does play some role in wounding for handgun rounds, but temporary cavity has little to no effect. Bottom line is that it looks like nobody is 100% certain of all of the effects. The "pressure wave" seems to be the biggest factor for stopping time, and it's dependent on many things, including energy and penetration depth. The pressure wave was discussed on THR in January 2006:
http://www.thehighroad.org/showthread.php?t=174568

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I agree with you that antibiotics and infection are a moot point in terms of stopping an adversary.

I am trying to figure out exactly what we are disagreeing on. You think energy injuries can occur at about 700 ft lbs, and I think its more like 1000 ft lbs. Isnt that really what we are disagreeing about? We both agree really fast projectiles do this, and really slow ones don't. The only difference is the cut off at which this occurs, and we are both basing our opinions on personal experience.

I think the only handgun cartridges we would really disagree on whether energy causes direct wounding would be 357 magnum and 10mm. Is that right?

The only difference is the cut off at which this occurs, and we are both basing our opinions on personal experience.

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mostly I dont think its a cut off as much as I think it starts becoming a bit of a factor around 500 ft.lbs. ie. 9mm 115+p+ loads have some although they may not penatrate enough where as 147 9mm almost always penatrate but don't have the shock.I belive at the 650-750 range you start having enough energy to do both pretty well.

This has been and continues to be an extremely useful and informative thread. It's great that it has remained on a "high road" plane. Some of my previously held concepts have been modified, or perhaps made more open to modification pending more information.

Regarding tissue death and cell death. It seems to me, that while that's interesting from a medical standpoint, it's not particularly germane to the issue of *immediate* effects on an attacker whom we want to *stop* ASAP. What happens to the attacker after stopping is a secondary consideration.

What I'd like to know is this. What factors deriving from the choice of *practical* defensive handgun round is going to make an attacker have to--or, want to--stop the attack?

The momentum proponents seem to be saying give me something that plows deep and makes a wide hole. The energy proponents seem to be saying, let's go deep and wide if we can, but also dump a lot of energy and create a big temp cavity for "shock value." Or, whatever. And, I'm certainly not trying to characterize everyone's positions so simply.

If I'm an attacker, I'll perceive a .45 FMJ that penetrates 8 inches into my body (let's assume no heart, aorta, or spinal cord hit) one way. What differences might I perceive from the wound of a high energy 9 mm that follows the same path and depth into the body? IF, repeat, IF there is more temp cavitation with the 9 mm, might the perception be one of more impact and systemic shock? Perhaps more pain? More likely to want to quit?

K

What I'd like to know is this. What factors deriving from the choice of *practical* defensive handgun round is going to make an attacker have to--or, want to--stop the attack?

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shucks I think the shear muzzle blast of a full house .357 *might* be a deciding factor,not that I'm gonna use black powder blanks,but if you"ve ever been around a 4" or less .357 mag at an indoor range you know it'll get your attention.

IF, repeat, IF there is more temp cavitation with the 9 mm, might the perception be one of more impact and systemic shock? Perhaps more pain? More likely to want to quit?

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maybe to the first and if there is the other two are defenitly yes.

I generally agree with what mavracer just said. Although energy of a handgun round may not directly cause observable tissue injury (in my opinion), that does not mean it can't help take the fight out of someone.

I am going to stand firm though on the fact that I don't think observable trauma occurs from energy alone of the usual service rounds. That would not include hot 44 magnum rounds, and I don't know if would include hot 357 rounds. I don't think 9mm rounds will cause this effect, even if they are +P. I do think 9mm +P hollowpoints are a good round, and in fact often load my Glock with Winchester Ranger-T's. I do this because I think this load expands well, penetrates deeply, and retains bullet weight well. I don't do it because I think it has enough energy to cause tissue death from energy alone.

The excess energy may contribute to incapacitation for other reasons though.

the momentum doesn't directly cause tissue trauma. Momentum increases penetration that causes trauma. I realize a bullet with no momentum will cause no trauma, but it causes no trauma because there is no penetration

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Would you agree it's the hole that kills?

And all other things being equal, a big, deep hole will kill better than a narrow, shallow one?

And that a through-and-through wound is as deep as it gets?

It seems to me that if you put a hole through the subject (in the right place, of course) -- be it a man or a moose, and it's a large diameter hole, you've done as much as humanly possible to "stop" the subject?

So I venture to say it isn't kinetic energy or momentum diretly that stops -- it's a wide (either originally or expanded) projectile going all the way through.

In the right place, of course.

So I venture to say it isn't kinetic energy or momentum diretly that stops -- it's a wide (either originally or expanded) projectile going all the way through.

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In terms of handguns, this is precisely what conclusion i've reached.

Obviously rifles and shotguns are a different story.

You wouldn't go far wrong in applying those same criteria to shotguns and rifles -- in rifles, the much higher velocities give longer ranges coupled with the ability to take bigger game reliablly, but the same dynamics are at work -- the hole kills. Make a big hole all the way through an elk or a buffalo, and you will put it down -- if you hit in the right place.

With shotguns, pellet density becomes a factor, but it's still the holes that kill. If enough pellets penetrate deeply enough, you will bring your bird down.

Would you agree it's the hole that kills?

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no from page 2 of this thread

I Know I've seen a bullet,that I chrono'd the ammo,was going less than 1300fps hit a 225 lb boar in the back muscle. that never entered the chest cavity,do enough damage to the lungs the animal died within' seconds.

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And all other things being equal, a big, deep hole will kill better than a narrow, shallow one?

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we all know that. we are talking about temporary cavity and shock value.ie. two bullets that expand to the same diameter and exit the one going faster, thus having more energy, will cause more damage.

And that a through-and-through wound is as deep as it gets?

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assuming all BG are the same size this may or may not be true a round that will compleatly penatrate a 6' 150 lb. BG might not a 5'6" 400 lb. BG.

It seems to me that if you put a hole through the subject (in the right place, of course) -- be it a man or a moose, and it's a large diameter hole, you've done as much as humanly possible to "stop" the subject?

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an even bigger hole?

So I venture to say it isn't kinetic energy or momentum diretly that stops -- it's a wide (either originally or expanded) projectile going all the way through.

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from page 1 of this thread.

Ever see a gunshot wound caused by a bullet with zero momentum?

Perhaps you are playing with semantics. Gunshot wounds are caused by bullets. But, bullets that have more momentum are more likely to cause more serious wounding, all other things being equal

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now that your caught up anything to add?

we all know that. we are talking about temporary cavity and shock value.ie. two bullets that expand to the same diameter and exit the one going faster, thus having more energy, will cause more damage.

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I don't think that's proven.

assuming all BG are the same size this may or may not be true a round that will compleatly penatrate a 6' 150 lb. BG might not a 5'6" 400 lb. BG

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If the bullet doesn't go completely through the 400 lb BG, then it isn't a through-and-through wound, is it?

I don't think that's proven.

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ok so a 32 acp. fmj will make the same wound a 30/06 fmj.don't think so.
have you ever seen a wound up close?

If the bullet doesn't go completely through the 400 lb BG, then it isn't a through-and-through wound, is it?

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Sorry, never seen ammo manufactures list penatration depth as through and through, must of missed that one.

ok so a 32 acp. fmj will make the same wound a 30/06 fmj.don't think so.

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If they both make the same diameter hole to the same depth, yes.

Now, normally the longer .30-06 FMJ will yaw inside the body, so the hole in that case will be larger for at least part of it's passage through the body.

have you ever seen a wound up close?

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I have killed many a deer, along with elk and other game.

And it was my duty and misfortune to have to inflict such wounds on men during the Viet Nam war.

So, yes. I have seen many a bullet wound close up.

Sorry, never seen ammo manufactures list penatration depth as through and through must of missed that one

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How does what manufacturers list or don't list contribute to the stopping power of a round?

If they both make the same diameter hole to the same depth, yes.

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male bovine fecal matter

So, yes. I have seen many a bullet wound close up.

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how then can you think your above statement is true?

How does what manufacturers list or don't list contribute to the stopping power of a round?

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because they know more about balistics and bullet design and performance than you or I do.kinda makes me belive they might have a clue how their ammo performs.

Vern,

Let's say a 30 cal steel ball traveling at 1500 fps has just enough mustard to traverse through a certain human target. You're not saying that the same steel ball traveling at 3000 fps and taking the same path through the body wouldn't be more destructive or have more stopping ability, are you?

K

Let's say a 30 cal steel ball traveling at 1500 fps has just enough mustard to traverse through a certain human target. You're not saying that the same steel ball traveling at 3000 fps and taking the same path through the body wouldn't be more destructive or have more stopping ability, are you?

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That's exactly what I'm saying.

If you were to shoot a thousand deer, men, what-have-you with those two loads, you wouldn't see a difference in actual results.

I am minded of Scandanavian data on moose (alg) reported in Handloader (or was it Rifle) magazine which compared "escape distances" for various calibers. As I recall, the 6.5X55 did a bit better than the .300 Win Mag.

Now it might be that your steel ball at lower velocity might not fully penetrate if it hit a large bone (such as the pelvis) and the ball with the higher velocity would. But that's about it -- it's the hole that kills.