Shocking Bullet Performance

By Ron Spomer Tue, Jul 25, 2017


While most gun-shot animals expire due to hemorrhaging, hydrostatic shock sometimes drops them like a bolt of lightning.

A recovered 300-grain Barnes TSX fired through a Cape buffalo from about 125 yards. It shows some expansion and a long shank, which helped carry momentum completely through the chest until the bullet came to rest against the hide on the far side. Even if the bullet didn’t smack the bull with enough hydraulic shock to damage its brain, it initiated enough hemorrhaging to incapacitate it. Best of both worlds.

While most game expires from bullet wounds due to hemorrhaging, shocking bullet performance sometimes drops it like a bolt of lightning.

Such a shocking event happened in front of my .30-30 Winchester M94 way back in 1968. A whitetail “button buck” dashed past about 50 yards out. I swung and shot. It dropped in mid-leap, never to stir again.

Whenever I see something like this, I assume my bullet struck the animal’s central nervous system. But every now and then a post-mortem reveals a lung, heart, or even kidney strike. Such was the case with that deer. The 150-grain flat-nose had smacked it in the central chest cavity. I know there might be a leg bone connected to a hip bone, a hip bone connected to a back bone, and a back bone connected to a head bone—but there’s no lung bone connected to anything. Why does any shot to the chest sometimes result in instant death when the central nervous system wasn’t touched?

Shock. At least that’s what’s been claimed these past 70 years or so. “Hydrostatic shock” or “hydraulic pressure shock” are other names for the phenomenon. The bullet transmits its energy to the animal’s blood, tissues, and bones, sending high pressure waves to various organs, including the central nervous system, i.e. brain. Lights out.

Weatherby magnum cartridges have been famous for doing this. Roy Weatherby didn’t coin the “shock” theory, but he did a brisk business around it. Weatherby sold big rifles and big cartridges that sent bullets crashing into game at velocities so extravagant beasts collapsed as if unplugged. Sometimes.

Some basic rules of physics are at play here. If you double the mass of a projectile, you double its energy, but if you double its velocity, you quadruple its energy. At 3,300 fps, a 115-grain bullet from a .257 Weatherby Magnum, Roy’s favorite, is packing a heap of shock energy. So Weatherby was knocking at the right door. Yet his high-velocity cartridges didn’t and still don’t floor game fairly struck every time.

In fact, game often runs off, merely wounded, leading legions of hunters to reject high-velocity cartridges and stick with big, slow bullets. (The Elmer Keith, Jack O’Connor feud.) The high-velocity, hydrostatic “shock” challenge is converting bullet energy into an effective destructive force every time, and bullet construction has a lot to do with that.

Most of us know that a solid bullet, the kind mandated for warfare but illegal for big-game hunting, zips through a body about like a target arrow. Regardless of its speed, it penetrates with precious little frontal area for transferring energy. Enter the soft-nose, hollow-nose, expanding-nose, and breakaway-nose designs, all made to increase bullet area to damage more tissue and transfer more energy. But not too much. Excessive mushrooming leads to minimized penetration, as explained in this blog we published earlier.

This is why bullet makers swamp us with so many variations on the theme: soft lead, hard lead, thick jackets, tapered jackets, bonded jackets, sectioned and walled jackets, monolithic copper hollow points—they try various materials and constructions to control how much and how quickly hunting bullets expand and how much mass they retain for deep penetration.

One popular theory postulates that a bullet should expand just enough to maximize tissue contact but not so much that it passes through the animal. Thus, bullet energy is dumped inside the animal for maximum knockdown effect. The problem is, it doesn’t always work.

Part of the reason is variable impact velocity. A 150-grain projectile from a .30-378 Wby. Mag. at 100 yards hits a lot harder than the same bullet from a .308 Winchester. But at some distance downrange the .300 magnum slows to less than .30-30 velocity at ten yards. How do you build a bullet to handle all that?

Another part of the problem is where the bullet lands. Shoulder muscle and bone initiate a lot more friction and expansion than soft lung tissue. And a third problem is when the bullet strikes. One theory has it that a hit to the chest when the heart is beating and systolic pressure is peaking has the greatest hydraulic effect.

A fourth problem is the animal itself. Is it alert or sleepy? Healthy or weak? Active and agitated, high on adrenaline? Shot through the heart, one critter runs off, another merely continues browsing, and a third falls dead instantly.

Time and again I’ve shot game from 1,500-pound buffalo to 25-pound coyotes with bullets carrying anywhere from 1,500 to 5,000 foot-pounds of energy. Some of those bullets remained within the body cavity, dumping all their energy, yet the animals did not collapse as if unplugged. Other bullets passed through, yet the game did collapse. And vice versa.

Another hydraulic-shock issue is bloodshot meat. Whether the hydraulic pressure of a high velocity bullet kills instantly or not, it usually tears tissue and blows clotted blood far from the wound channel. Clearly, hydro-pressure is at work, and its not work that venison gourmands appreciate.

Whether you call this “knockdown power” or “hydrostatic shock,” you have to admit it surely isn’t consistent. So what’s going on?

In all honesty, I don’t know for certain, and I’m not certain anyone else does because there are strong arguments and evidence on both sides, including contradictory studies since 1947 on wounded soldiers as well as hogs and game animals as large as Cape buffalo. Some research has shown that “vascular pressure impulse” from a chest or abdomen hit can carry enough energy to damage nearby tissue the bullet doesn’t touch.

Watch videos of bullets passing through ballistic gelatin and you can see the temporary wound cavities in their wake. Slow-motion videos of animals at the time of bullet impact show dramatic contortions of the body as tissues flex, bulge, and absorb the energy. Energy waves are clearly making an impact. It can even reach from the thoracic cavity to the brain causing a precipitous rise in intercranial pressure. One study using EEG readings on the brains of pigs showed that a bullet strike as far back as the thigh caused neural and vascular damage in the brain.

Jim Carmichel once reported on a veterinarian-controlled study during a buffalo-culling operation in Africa. All buffalo were shot in the heart/lung. Some fell instantly; some did not. Post-mortem examinations revealed massive rupturing of brain blood vessels in those that collapsed at once. Those that didn’t collapse immediately showed no such rupturing. Sounds like good support for that systolic blood pressure idea. Anybody know how to time your shot for that?

This must have been what happened to my wife’s Mozambique buffalo shot with a Blaser R8 rifle spitting a 300-grain Barnes TSX. The bullet passed through the chest, broke no bones other than a rib, and lodged against the offside hide. When the herd thundered off, there lay the stricken bull—on its side, head up, glaring at us but unable to rise and charge. A mercy shot to the heart ended it.

We didn’t autopsy the brain, but could there have been vascular brain damage from that first shot? What else explains the infamously aggressive Cape buffalo not rising to mayhem? All his limbs were intact.

Clearly, bullet shock works sometimes. But not all times. I’m guessing it’s much like that boxer’s punch. Sometimes what looks like a perfect, knockout punch barely fazes the opponent. Other times a Phantom Punch drops him in a heap à la Ali/Liston. The question is this: Do we want to trust to something that works well only sometimes?

The good news is we don’t have to. High velocity coupled with controlled-expansion bullets gives the best of both worlds. The hydrostatic force is delivered, but the bullet remains in one piece, expanded, to penetrate deep and physically damage vital organs. If hydrostatic pressure waves terminate the animal instantly, great. If not, hemorrhaging should. Of course, there remains the bloodshot-meat issue, but it can usually be avoided by shooting to miss major muscle groups.

Thankfully, each of us is free to hunt with big, slow bullets, small, fast bullets, or big, fast bullets. Regardless, we always have the responsibility to park those bullets in the right place. Accuracy uber alles.

quote:

Weatherby magnum cartridges have been famous for doing this. Roy Weatherby didn’t coin the “shock” theory, but he did a brisk business around it. Weatherby sold big rifles and big cartridges that sent bullets crashing into game at velocities so extravagant beasts collapsed as if unplugged. Sometimes.

All I can tell you is NOTHING electrifies deer than my 257 Weatherby with good old 100gr Hornady Spire Points. Fifty four kills and NOT ONE took a step.

While I generally agree with this I also think it depends on the animal. Deer are more likely to fall quickly to a high velocity bullet but a moose for example falls quicker to to a bigger, slower bullet. Not that the opposite in either case won't work.

What I do believe is pretty much all cartridges developed since the beginning of the twentieth century have progressed to smaller diameter and higher velocity. They also have become more effective. So strictly saying that bigger is always better simply ignores reality.

And yes I love my .257 weatherby too - in its place.

Blood pressure is also higher depending on the body having enough water. (Check your own b.p. when dehydrated.) Access to water figures in to African animals and resistance to hydrostatic shock? Glad Spomer references Carmichael on this. I find him hard to listen to but easy to read (like Carmichael.) Thanks for the article!

Also, consider the state of awareness / tension due to adrenaline level. I'd asked why long-range kills seem to be so different on film. I believe the shot "out of nowhere" that lethally connects while the bullet speed has diminished comes into play...

In a age of almost unlimited access to information it surprises me that a author of a article in a magazine would come up with this !

I have hunted a few times with Spomer. Guy is hilarious - and very witty.

I have always wondered about such articles and the many variables that are NOT mentioned.

I have posted before about a bullet hitting a rib. Firstly the bone pieces are ground up like coarse grit and they spread all over the lungs & heart. I have seen RDT deer lungs like rags after a rib hit.

The spine is also shocked by the strike on the rib.

Most Cup & core bullets lose (let us assume) 40% to 65% of weight. Where does all that lead and jacket material go? How many DRT animals got a piece of lead or jacket wedged in the spine and never notices or found when butchering?

Then we come to physiology. What happens if the animal is breathing in when hit in the lungs. Does it choke on the blood as it is taking a breath?

What happens when the bullet hits the heart as the top part of the heart is pumping out blood? Does it cause more immediate incapacitation compared to a lower chamber pulse?

I have seen a report (with photos) of a buffalo hit with a 458 solid in the center heart and surviving for over 30 minutes before it was finished off. The hole would just shut with each heart beat!

Shock (energy transfer) and penetration are both important, and both rely on shot placement.

Basically confirming what most already knew.

The world of terminal ballistics is a world that lives in 3 distinct velocity and time zones.

There is the slow world of baseball, cricket, tennis and billiards where velocity is measured in slow world measurements; miles per hour or Km per hour.

Bullets live in faster world , fps or m/s if you are metrically inclined or where a ballistic event may span a timeline of a few milliseconds
( the ignition of a charge of powder, the rise of a pressure curve, the rise and collapse of the pressure curve associated with the temporary cavity ! Total barrel time or total time it takes bullet to come to a stop in a target. all fast but actually still slow !

Then there is the ultra fast world where shock waves reside ! Where time is measured not in milliseconds but in nanoseconds. Where pressure rises from zero to 100 Mega pascal in less than 10 nanoseconds and as fast as it has gone up it drops exponential fashion to a negative value.
This is a world of acoustics where a acoustic wave is propagated through the tissue at a velocity roughly that of the speed of sound in water. It does not move tissue it does not damage tissue ( well not in a way we can see it it ) if it did we would not be using it to break up kidney stones or treat pain of tendinitis.

The wave of pressure caused by a bullet's passing is not a "shock" wave, it is a simple sinusoidal pressure wave, yes its awesome in what it can do but it's capacity has limits and many tissues have ability to deal with these waves without sustaining much damage.

Well, except when you add the hydraulic effect to it then pressure waves can do further damage. But yes acoustics in enough volume can do damage.

This is beginning to sound as silly as that claim of shooting a charging buffalo while he is breathing in, will drop him dead.

If you shoot him while he breathing out, he will kill you no matter where you hit him

I have no idea how many animals I have shot, or seen being shot.

From tiny antelopes to elephants.

No matter what ideas one has, you will come across one that will turn all your previous thoughts upside down.

I have seen animals drop dead from an extremely marginal shot, where no vitals have been hit.

And I have seen animals with major organs destroyed, and still run quite a distance!

Here are a couple of examples with impala.

Both were shot with bullets developing approximately the same muzzle velocities, both were roughly the same distance.

1. 375/416 Rigby Improved. 300 grain Barnes X, at a muzzle velocity of 3140 fps.

Impala was less than 200 yards away. Bullet hit him in the heart. Tore it to pieces. He ran like a bat out of hell for over a 100 yards, and dropped dead.

2. 270 Ackley Improved. 130 grain Barnes X, at a muzzle velocity of just over 3100 fps.

Impala was less than 200 yards. Bullet hit him low in the neck, not touching any bone, just a flesh wound. He dropped dead in his tracks.

3. 375/404. 300 grain Barnes X, at 2800 fps.

Impala was feeding less than 50 yards away. Facing towards us. Bullet hit him at the junction of the neck, going all the way through his body, and stopping under the skin in his rear end.

He stopped feeding, looked up, and started walking very slowly a couple of yards. Stopped, then lay down. It took a while for him to die.

Now I would like to hear what all the experts on terminal ballistics explain all this.

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Originally posted by jorge:

quote:

Weatherby magnum cartridges have been famous for doing this. Roy Weatherby didn’t coin the “shock” theory, but he did a brisk business around it. Weatherby sold big rifles and big cartridges that sent bullets crashing into game at velocities so extravagant beasts collapsed as if unplugged. Sometimes.

All I can tell you is NOTHING electrifies deer than my 257 Weatherby with good old 100gr Hornady Spire Points. Fifty four kills and NOT ONE took a step.

It is a fabulous caliber for that kind of work. I have had similar luck with the 25-06. Bang flop!

I've never chronographed, but my 7-08 has dropped most things dead. I just feed it whatever ammunition I have. Maybe old Remington core-loct, federal something. It just works. I don't remember the grain. Maybe 140 or so.

I still wonder why I bought other rifles. Well....

Just throw a big rock (.510 caliber 570g bullet at 2100 to 2400 fps) the issue seems less important.

quote:

No matter what ideas one has, you will come across one that will turn all your previous thoughts upside down.

As I have maintained for a long time, you shoot at enough stuff or watch enough stuff get shot and there will always be the occasional oddball circumstance that goes contrary to all past experiences.

quote:

Jim Carmichel once reported on a veterinarian-controlled study during a buffalo-culling operation in Africa. All buffalo were shot in the heart/lung. Some fell instantly; some did not. Post-mortem examinations revealed massive rupturing of brain blood vessels in those that collapsed at once. Those that didn’t collapse immediately showed no such rupturing. Sounds like good support for that systolic blood pressure idea. Anybody know how to time your shot for that?

That's the most sensible explaination I have seen yet for some of the drop-to-the-shot experiences I've witnessed. Over the course of raising a couple young hunters, I've witnessed the full spectrum of shot placement and animal reaction. While many of the "drop immediately" shots where the result of a bit too far forward in the shoulder region and severing the spine as it dips thru that area, some I could not explain. Too far back to be a good lung shot, too low to severe the spine, yet the animal's legs turned to jelly and it fell never to move again. Like a brain shot, but no where close to the brain. Perhaps perfect timing and ruptured blood vessels in the brain explains it.

quote:

Originally posted by jorge:

quote:

Weatherby magnum cartridges have been famous for doing this. Roy Weatherby didn’t coin the “shock” theory, but he did a brisk business around it. Weatherby sold big rifles and big cartridges that sent bullets crashing into game at velocities so extravagant beasts collapsed as if unplugged. Sometimes.

All I can tell you is NOTHING electrifies deer than my 257 Weatherby with good old 100gr Hornady Spire Points. Fifty four kills and NOT ONE took a step.

Jorge is correct, on this one, and I think Spomer's article showing that one of the findings was the fact that the brain was damaged being evident is why they drop like a rock kills.

The fact is I have experienced the same effect on mule deer with a little Mannlicher MCA rifle chambered for 243 Win with a hand load using the little Hornady 100 gr soft point at 3000 fps velocity. My aiming point on deer has always been tight up against the back of the shoulder to avoid meat damage on the shoulder and at the same level as the heart! My most often experience was all four legs snapping up to the belly and the deer falling down on his belly, dead. This happens more often than not with this same little 100 gr Hornady bullet and the 3000fps velocity.

The thought never crossed my mind so I never checked the brain for damage. However that makes perfect sense! The sudden change in pressure in the chest cavity may have compressed the heart violently enough to force a rush of blood in the carotid arteries into the brain cavity causing sudden death.

The next one of these I get I will certainly open the scull and examine the brain for damage.

Very fine article, Dogcat, thanks for posting it!

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I've also hunted with and guided Ron Spommer. He is a fun guy to hunt with and he's a very good shot and in good shape. The guy can cover some ground.

Good grief people ! There is no evidence that a bullet passing through the thorax heart or large vessels have the ability to "damage the brain" !

quote:

Originally posted by ALF:
Good grief people ! There is no evidence that a bullet passing through the thorax heart or large vessels have the ability to "damage the brain" !

Wait for it.

Someone is going to tell us he can actually tell when a buffalo doing his systolic and diastolic blood circulation, and times his shot accordingly

The assertion that a pressure wave can be transmitted from one point in a solid albeit a water containing visco elastic solid is actually quite valid. Shooting high velocity bullets at small living targets and seeing them 'blow apart" is enough evidence for some.

Historically many have made this observation and some became quite famous for this. The so called "Strasbourg tests" and the published work of Marshall and Sanow and many many others.

To prove or disprove the assumption many studies have been conducted in living animals and in test media using pressure transducers. Some very prominent modern wound ballistics experts have spoken against the theory.

To delve into this would be quite a undertaking simply because there is a whole library of data out there that deals with the subject.

From a simple logical perspective we have to contend that the chest contains two lungs which in essence is a organ filled with air. Air is a poor conductor of a pressure wave and should the bullet be so lucky as to find one of the big vessels in the lung a pressure wave is damped out by the very normal anatomical / physiological function of arteries.

A shot to a large artery or worse vein need not concern itself with indirect damage to the brain
the animal will bleed to death in short order.

quote:

Originally posted by Saeed:

quote:

Originally posted by ALF:
Good grief people ! There is no evidence that a bullet passing through the thorax heart or large vessels have the ability to "damage the brain" !

Wait for it.

Someone is going to tell us he can actually tell when a buffalo doing his systolic and diastolic blood circulation, and times his shot accordingly

You have to wait until the Buffalo chooses how to die. Then he will fill his heart with blood and look at you like you owe him money. That's the time to shoot.

quote:

Originally posted by surestrike:


You have to wait until the Buffalo chooses how to die. Then he will fill his heart with blood and look at you like you owe him money. That's the time to shoot.

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quote:

Originally posted by surestrike:

quote:

Originally posted by Saeed:

quote:

Originally posted by ALF:
Good grief people ! There is no evidence that a bullet passing through the thorax heart or large vessels have the ability to "damage the brain" !

Wait for it.

Someone is going to tell us he can actually tell when a buffalo doing his systolic and diastolic blood circulation, and times his shot accordingly

You have to wait until the Buffalo chooses how to die. Then he will fill his heart with blood and look at you like you owe him money. That's the time to shoot.

Does this apply equally to farm bred, ear tagged pets with a verified birth certificate too!

I guess it is time for me to sell off all my rifles and become a vegan!!!!!!!!!!


Concepts have changed too fast for my little simplistic ideas, such as just start putting holes in a critter until it decides to die!

Over the years and all the various Gun Writers whose articles I have read, Mr. Spomer is one of the few I just really do not agree with all that much.