ALF, I think we are in agreement, just looking at it from different directions. In my example I was thinking of larger, slower projectiles in terms of smaller diameter, larger penetration wounds. Useful in hunting larger, tougher animals, also somewhat comparable to the same projectile at lower velocities. One also has to consider the expansion of the bullet at different velocities. That can change the wound channel a lot!

And yes, a chicken reacts differently to a deer when hit with the same bullet. Now we are getting into the toughness of the animal and the 'appropriateness' of matching the bullet you shoot to the game being pursued.

Alf, I thought your distinction between hydrostatic shock and physiologic shock makes great sense. Can you take it a step further for us? My thoughts: Any projectile entering an animal will cause hydrostatic shock, the intensity of which will vary with mass of projectile, shape, velocity etc. However, that hydrostatic shock will not necessarily cause physiologic shock unless it disrupts the CNS directly or causes immediate BP loss and therefore almost immediate loss of oxygenation to the brain. If the hydrostatic shock is massive and near enough to a vital location of animal (spine, brain, etc) then the hydrostatic shock may cause physiologic shock without a direct hit on the CNS. Would like your thoughts. Bob

Mostly Myth!

Here's how it works.
If You shoot a coyote with a 270 with a good expanding bullet at ...say...100 yards, you'll find that the combination of velocity and expancion will blow a very large hole through the coyote. Now...if the coyote weighs 35 pounds, and if you were to take ALL of the destroyed tissue, from that 35 pounds, you'll find that the bullet destroyed about 4 pounds of the coyote. That's about 9% of the live weight of the coyote. And the 270 bullet goes through without any problems because the coyote is only about 8 inches through and through.
Next we shoot a 240 pound mule deer with the same bullet. if the bullet goes through (most will in a 270, except for the worst ones like the Nosler ballistic tips ect..) we do the same experiment. The total of tissue destroyed in a big deer (about 13-14" through and through) is about 8 pounds. This includes lung tissue, heart tissue, ribs bones, meat, skin and so on..) 240 minus three and a half % is 232 pounds. So lets say the 270 destroys only 3% of a deer, but 9% of a coyote. It's 3 times more effective on coyotes than deer.
Next we shoot a 675 pound elk. Again we say the bullet goes through, and the dammage will be what?.... about...,10 pounds!?!? because the elk is bigger. So, just to illustrate, let go with the 10 pound figure. 675 minus 1.35% is 665 pounds. So we can say our 270 destroys 1.35% of the "total Elk".
If we shoot a moose, at 1300 pounds with the same 270 the bullet may or may not go through. If it doesn't, the animal dose not bleed out as fast. Remember the rule from basic first aid? If someone has a sucking chest wound You should seal it off, and keep the blood INSIDE the body. They may live long enough to get to a doctor. Right?
So case #1
The bullet goes through. It destroys about 11 pounds. The wound channel won't be very large on the other side of a moose. So it's not going to destroy much more moose meat than it did elk meet. The moose is 1300 pounds minus 11 pounds. That's only .75% of the "total moose".
Case #2. same equation... but not as rapid bleeding from a wound when the bullet dose not go through (Here's the BEST arguement for premium bullets on BIG game) Now we are trying to kill the moose with only .75% of his total body weight destroyed, and He's not bleeding very fast. If You havent hit him really well (bone) he's going to do some traveling before he drops. You'd better be a good tracker if Your not a good shot!
I love the 270. In fact I am on the 3rd barrel in my own 270, but I don't choose it as my moose gun. It's good for elk with good bullets, but it dose not kill them as well as my 338-06 or my 375H&H if I don't get a broadside shot. Broadside, I can't tell any difference between the 270 and the 375 on elk, but you REALLY CAN TELL IF THE ELK IS QUARTERING!!!!!
The hydrostatic shock theroy dose not seem to work in the real world.
I have killed 4 moose in My life. 2 with a 375H&H, 1 with a 348 Winchester, and one with a 62 caliber flintlock. The only one that fell at the shot was the one with the flintlock. The other 3 fell soon after the shots, but not for a few seconds, and all were hit well in the chest. I have also killed some elk with the 270, and they fell instantly, but I hit them in the spine or neck. I have seen 3 others shot with 270s, and 2 died ok, in a few seconds, and one other fell instantly. I can't count the deer and antelope I have shot, and seen shot with 270s, and all but maybe 7-10 fell instantly. (I can't immagine a chest shot coyote ever leaving the spot he was hit on..can You?)
If the animal is small enough, and/or the caliber big enough to "blow them in two" I guess "hydrostatic shock" could work. But what kind of gun wound that be??? Look again at the moose and the coyote! 9% of 1300 pounds is 117 pounds!!! Totally destroyed!!?? I know only a few "guns" that will do that, and they all belong to the Army and Marine Corps, and they won't sell us one. (Besides....the rockets are too expensive)

The bottom line....
Bigger guns/bullets for bigger game.
Too much speed with the wrong bullet is BAD NEWS, because the bullet isn't a bullet when it blows up! It's just a very small shot charge! Good for snakes, but not much more.

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Hello once again.

To add my thoughts to ALFs post I would like to relay some info which was told to Me by Dr. Moorehead, an old friend of Mine.
Dr. Moorehead was a field surgeon in Korea and Viet Nam. He was also an emergency room surgeon in a large hospital in Califorina for about 30 years. Mr. Moorehead was an avid hunter all over the world.
One of the myths which keeps getting repeated by "knowledgeable" people about gunshot wounds is "the deadlest one of all is the 22 L.R. It goes in and bounces around, and the doctors have a hell of a time trying to find and fix all the dammage" Dr. moorehead says He's heard this many times from other trama surgeons. But he corrected them by pointing out a few things.
#1 They are working on the victim! He's alive!
#2 They are often hit in the body, many in the chest....these 22 victims.
#3 is a question.... "how many 44 magnum, 357 magnum, 30-06 victums have they worked on who were hit in the chest? Mr. Moorehead told me when he asked this question to his collogues, most said "uhhh....none". See, they don't come to the emergency room. They go to the "cold room"
I am the originator of Cast Performance Bullet Company. I no longer work there, but I still have a keen interest in ballistic performance. I have seen hundreds of bullet wounds in animals which were dead, and quite a few in people who were both dead and alive. The world of brush war is not the same as hunting.
The good doctor ALF is correct in his observations. However, there are some things that need to addressed. Military men don't opperate alone, and when they are wounded they are taken (if at all posible) to a field surgeon. Or to a field morgue. They Are TAKEN. See, in the hunting world, the animal just makes it's escape if it can. Sure, it may die, but when and where? Shoot an elk in the lungs with am M-16 and I'll give you 100 to 1 odds it will die. I just don't know if the hunter will recover it or not.
If a doctor is working on someone, they are alive. ALF is correct in saying that a non vital hit at CLOSE RANGE (range at which the bullet IMPACTS at 2700 feet per second or more) is going to be worse than the same hit with a low velocity hit with a bigger bullet in the same place, but we are talking about hits in the "right place" in animals.....arn't we?
I have a LOT of experience with the M-16 from my days in the Marine Corps, and I can tell you for sure and for certain that the M-14 with it's 147 gr 30 cal bullet will penetrate more bone and meat than the M-16 55 grain bullet at 400 F.P.S. faster.
If we were to shoot some deer with military 223 ammo (I have)and some deer with military 308 ammo (I have) we'll find that they both do OK in broadside shots. The "223 deer" die quick enough at 100 yards and under, but not very quickly at 200 yards. The 308 is about the same from 100 and less, but much better at longer ranges. And the 308 dose fine on quartering shots. (in fact even better than when the deer are sideways) but the 223 fall down badly on the quartering shots. I have killed 3 deer and one antelope at 150-175 yds with a 44 magnum carbine, and it was also far more effective than the 223. Yes ...they all died, but I am talking about how fast they went down, and how well the bullet penetrated and bled them out. I would still hunt deer sized animals with 44s 308s or even 243s but I have pretty much given up on the 223. At close range it dose work, but it is never going to be as good "all around" as the bigger guns.
So how dose this all relate to "hunting rounds"?
If your ultra mag wizzbang penetrats the chest or liver of your game and if the bullet holds togather to get through, it will probably destroy more of the organs than ...say...a 30-06. (dose that matter? maybe....maybe not.. if the 30-06 also kills from the same shot in 5 seconds or less..)
But I also note that the good doctor still recommended a "big gun" for the bigger game.
As I said in My first post, the "hydrostatic shock" of a round can work IF there is enough of it compaired to the size of the animal being shot, but I can tell You from my experience as a ballistician, it only works at IMPACT velocity of 2700 F.P.S. and greater, and then only if the bullet dose not come apart before it can get the job done.
In the hunting field, death in 6 minuts after the shot is not good.
In a war we don't care, as long as our enemy stops shooting at us.

Just my thoughts.............

I have read most of the threads and would like to ask only 1 question:

When an expanding bullet penetrates does it push a column of flesh/tissue in front of it?

the analogy of dropping a stone into water would be applicable here as the water in front of the stone (depending on shape)would be pushed forward.

I am sure that if examined that the fragments of bone and flesh, come from both sides of the animal!! therefore it pushes rather than sucks.

just a thought

griff

HTL, the author of the terminal ballistics paper on the mindspring link used to post on AR a fair amount. I have continued to follow his website as he has continued to expand it. His material is excellent, and is not refuted by experience.

I also correspond with a hunter and teaching professor of veterinary medecine whose professional opinion is the same as HTL's.

A third source is Norbert and his website on his SuperPenetrator bullet design.

My personal research in terminal effects agrees with all three of these gentlemen and those who label "hydrostatic shock" a myth. The term itself is also arrant nonsense, but Bubba continues to use it and it goes on and on like some kind of energizer Cape buff.

jim dodd

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exactly

Is "Hydrostatic" shock a myth? I think one of the first problems with that question is many folks have quite strange ideas what is meant by "hydrostatic shock"... Some guys believe that a shockwave from a chest shot animal will travel through the tissue and even through the veins and arteries and cause some sort of brain damage! in that sense,I beleive that it is a myth...

If all other parameters are equal ,does an increase in velocity of a round mean it causes more tissue damage? Generally speaking yes...Does that mean it has better short term killing potential in a hunting situation?

Maybe, maybe not!

There are just too any other factors which are equally important from bullet construction/performance to the size and physiology of the game itself.

I have read reports that indicate that size of the permanent wound cavitation is the important issue and that effects regarding secondary wound cavitation are often less predicatable...

I think the latest word on this subject is perhaps the most cogent. Most of us are in violent agreement, but a great many things have been debated here.

Let's try to separate them:

1 A phenomenon that kills game instantly when shot
2 A phenomenon that knocks down/out game instantly when shot
3 A pressure wave that forms around a projectile passing through a fluid or semi-fluid medium
4 Proper terminology to describe any or all of the above

Based on my study and experience I would aver that the first premise is true, but very rare. People have been killed by a hockey puck that hit them just right. Weird things happen. That is a cardio-neurologic phenomenon, in our case caused by a pressure pulse in proximity to (I'm guessing here but drawing on exchanges with pathologists) the heart and/or lungs. I don't think any of us can design for this or count on it in the field.

Situation number two is similar to the point of being practically indistinguishable in almost all cases, but important distinctions apply. In this case, a much more common form of injury is received (again caused by a pressure pulse, but proximal to the upper spine) that caused momentary paralysis or stunning. In almost all instances the wound that causes this effect is also a devastating lung shot, so the game animal bleeds out before it recovers its wits. In some cases (and many of us can attest to this), the animal suddenly recovers and bounds away with bewildering animation whilst we stare stupidly, fumbling with our rifle to shoot a fleeting beast we thought was already dead. The important observation here is that no weapon that one can shoot from the shoulder will deliver a blow of such magnitude as to kill big game simply with a pressure wave. If it could then it would pretty nearly kill the shooter! The time history of the rifle recoil and the bullet penetration event are very similar. People wearing soft body armor get the effect of maximum impact (by reducing the penetration depth) and its quite survivable.

The third matter of discussion, as so many have powerfully argued, is of course a real physical behavior. Projectiles passing through solids and generating forces well in excess of the flow stress of the target medium will cause that medium to behave much like a fluid. When the projectile's penetration velocity (always less than its impact velocity, right?) is below the sound speed of the material (and things denser than air have much higher sound speeds than 1000 fps) then the pressure wave formed off the nose of the projectile advances ahead of the projectile through the medium. As such, there is no "shock wave", which would have meant that the projectile was penetrating faster than the sound speed of the medium (flesh has a sound speed of more than 4000 fps). So, in that sense, "shock" is the wrong word.

Shock is also the wrong term medically speaking for what we have been describing here, though (as our friend Alf can tell us in some detail) ballistic wounds do produce the medical effects termed shock. Its just different from instantaneous death or unconsciousness.

Finally, I personally detest the slang term "hydrostatic" as applied to ballistic events. I'd be happier if the slang were "hydrodynamic shock". At least then we'd be speaking quasi-meaningful slang jargon!

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Alf and others,

I've been reading this with some interest, and one aspect has been ignored--maybe b/c it has no bearing here. Does the supersonic nature of the projectile influence the final outcome? I know that the shock wave created when a projectile surpasses the speed of a sound wave can have destructive force (ie knocking in windows nearby when an aircraft does this). Could this contribute significantly to the phenomenon of the larger-than-projectile hole, or cavitation?

.

While I'll concede there is a pressure build up ahead of the projectile, I doubt sufficient pressure to crush tissue extends beyond the diameter of the projectile. In other words, I don't believe that pressure waves cause the damage seen outside the bullet's path. Rather, I believe such damage is the result of the stretching of the tissue in this region.



As the bullet passes, the crushed tissue is, of course, displaced both forward and laterally. Increasing the velocity 20% increases this lateral velocity 20% as well. Using a more blunt nose will increase both the lateral velocity as well as the amount of tissue shoved aside. An expanded bullet also shoves aside more mass of tissue.



When the momentum of the displaced tissue reaches a certain point, the elasticity of the surrounding tissue cannot contain the expansion. In other words, the surrounding tissue is torn. The tearing is increased when bits of bone or metal perforate the tissue before the expansion begins.



I read that somewhere , and it sounds good to me.

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Brent,

The action at a distance example of dynamite in water you mention has a very real physical mechanism that we can measure. Water and gases too are good at carrying longitudinal waves.

I was getting at theories that claim to observe an action at a distance for which there is no physical mechanism.

I will get to Alf's arguments as soon as I get my chores done. Suffice it to say over-long posts are the equivalent of saying the same thing, louder.

jim

I've always thought that terminal ballistics were magic and at very best extremely unpredictable. Theory seems to be largely useless and subjective.

I've killed 63 whitetails and have seen several hundred more killed and know that has worked for me and my friends are bullets of 120gr-165gr weight, 27-30 caliber, reasonably sturdy construction and moving from 2700-3000fps kill deer in their tracks with a good lung or heart hit.

I've seen countless deer wounded with good hits with 243's, shotguns and 45-70's. They often die within 100yds or so of where they were hit but in thick woods that can spell disaster.

Smaller calibers seem to have intermittent penetration problems especially when encountering bone or raking shots. Heavy bullets and those of big calibers seem to lack the ability to put them down immediately and permanently.

Seems that from my "limited experience" that shock might be very important but you can draw your own conclusions.

I'll stick to what seems to work every time for me now. A 150gr Nosler Partition moving 2750-2850fps from any angle through the vitals of a whiteail causes instant death.

No running off, no getting back up, no doubts or uncertainities.

I really don't think it's rocket science.

Just my experience.

$bob$

OK, Alf, that DiMaio & Zumwalt article I'll have to locate through the local library. I've haven't dug too deeply into this subject, but that is the first reference I've seen which indicates the pressure pulse is high enough to damage tissue. The theory I mentioned was in an article referring to the work of Fackler. If I recall, significant damage due to stretching in the temporary cavity begins with bullet passage around 2400 fps.

Did D&Z note what pressure is required to reliably disrupt tissue? I'll admit 3 ksi certainly sounds enough. At what fps (in ths flesh) is this pressure pulse significant? How far around the bullet (diameters, I presume) does the effect typically reach? As I said, I'll need to find a copy of that -- thanks for the reference.