Hydrostatic shock

5

.50cal packer

New member
Ok. So this question is for handgun hunters, but anyone with more knowledge than me, please chime in. " that should be an enormous amount of people."
But if rule of thumb stands, it requires 1000 ft lbs energy, to require hydrostatic shock, wouldn't that eliminate all handgun hunting for deer, ect... I haven't checked the 500 S&W, but from what I have seen ballistics wise, even the .44 Mag doesn't hit that mark. We can argue, shot placement all day long and I get that. Hogs can be slaughtered with a .22 short at point blank range. We can argue distance as well. We hopefully won't
 
The "1000 ft/lbs" is a pretty arbitrary number used as a very general rule.

It really has little to do with "hydrostatic shock", and that's not what kills the game in most cases anyway.

Death is generally a result of exsanguination due to tissue damage from the wound channel that cuts off the supply of blood and oxygen to the brain.

Improvements in bullet design have made it easier to do more damage with less powerful cartridges than when the " 1000 ft/lb rule" was established.
 
+1 Snyper

The question posed is done so in such a way that the answer would be yes, but saying it takes 1000 ft. lbs or energy to kill a deer is not a true statement. Archery hunters take deer with tools that don't deliver 100 ft. lbs of energy, instead their weapon of choice kills by depriving the animal of blood and/or oxygen.
 
Snyper and AllenJ,

I apologize. There was no intention, of trickery, for this question. I completely understand, what you're stating. A bow or a reasonable facsimile there of, doesn't come near the 1000 ft lbs. Thinking in terms of Native Americans, killing bison with their bows and spears, puts that train of thought out the window. So why, were we taught growing up, ft/lbs has a minimum for medium size game? I can easily assume, in some backwoods places, we have unethical folk, hunting deer and such, with a 17hmr. Each state has a minimum regulation, on firearms. As my old state of, IL, had a 20 gauge and up. "Shotgun season." As no rifles could be used. But handgun season had restrictions of a case length, of 1.4" max or that could have been OAL. I don't recall, right of hand. Leaving the 2 main hunting handguns on the table and everything else off. The .45LC has attributed to many of kills. So why confuse the situation with limits, when they don't apply?
 
Last edited:
I think the reason hunters are concerned with a minimum ft/lbs number is to keep weak or marginal calibers out of the equation. For example, most hunters would agree that a .30 Carbine is just too marginal for ethical deer hunting. Same would hold true for some of the obsolete calibers that you still see floating around (like 32-20).
 
Many, many years ago, the first time I read that "it takes X number of ft. lbs. to kill a deer" I questioned it and I still do today. It depends on what bullet you're using and sorry about including this but the placement of the bullet. Shoot a deer in the brain and you'll only need enough ft. lbs. to pierce one side of the skull and the brain tissue, no exit wound required. By disrupting the central nervous system you'll stop the brain from telling the body to do anything, the result is death. Same goes for spinal shots, enough energy and damage to the spine results in death. I don't know how much energy that is but I feel safe in saying it is far less than 1000 ft. lbs.

Why do some say it takes X number of foot pounds is beyond me, my guess is they are trying to put a number on something that can't be measured accurately given all the variables.
 
Ft-lbs of energy does NOT equate directly to Hydrostatic shock.

Taylors knock-down formula is one that incorporates bullet weight, diameter and velocity (adjust for range) as a comparison between cartridges. However bullet design and shot placement are still factors that will push actual terminal performance one way or the other.

Hydrostatic shock only comes into play at velocities above some number, which is arguable. 2100 to 2300 fps is the range most ballistics experts agree that it occurs above. On some types of game, it is a thing that can let you get away with a faster, lighter bullet and still make effective anchor shots. But it should not be considered the end all that if the round strikes at 2300 fps or faster, all you will have is bang-flops. It still take more than just hydrostatic shock.

There are actual numbers for ft-lbs of energy that it takes to penetrate through on live tissue. Every piece of tissue (skin, muscle, bone, lung, cartilage, fat) has a certain amount of energy that is required to penetrate and traverse. While most of my work in that area has been done on humans that were shot, there is some validity for the minimum ft-lb threshold given a certain game animal. Virtual autopsy using MRIs is time consuming and expensive, but I use what I learn there to translate to shooting game.

In my experience, most hunters use enough, and some too much, gun. But most hunters spend way too little time at the range practicing. If the practice sessions would increase, we would have less wounded game and less discussions on required stopping power. :)
 
Gunwriters love to use muzzle energy as a quality metric because it is easy to use, just multiply bullet weight by velocity squared. Squaring the velocity means it is easier to shill for the faster cartridge, because, increasing velocity inflates the kinetic energy number by the square, and that of course, looks all impressive. Unfortunately kinetic energy is not conserved, momentum is. Momentum is mass times velocity. You can increase mass, which is relatively hard and results in horrible recoil, or you can increase velocity, which increases pressure, but at the end, you don't get these huge number increases which happens with kinetic energy.

And based on what I have seen, neither kinetic energy nor momentum are good predictors of lethality, though it is my opinion that momentum intuitively seems to make more sense. I more or less fall into the Fackler camp which argues that the bigger hole, bigger crush space, and a hole that promotes blood loss, is the better predictor of lethality. Dr Fackler basically said : "if it bleeds, and it bleeds enough, it will die." This is true for all the animals, big or small, in the animal kingdom. Blood loss is 100% fatal.

This is one reason shot placement is so critical. If you can place your shot in an area chock full of blood vessels, arteries, like the heart/lung area, you can induce massive blood loss that will kill your target quickly. Shoot something in the hoof, and the poor creature will run off to die of infection.

These kinetic energy numbers which are now chiseled on Gunwriter stone were always arbitrary and never backed up by anything involving rigorous analysis and test. Gunwriter wisdom is basic nonsense repeated endlessly until it becomes fact. Unfortunately the basis is nothing more than "group consensus". So it falls into a category of belief, like superstition or a religion. Dr Fackler rails against Gunwriters in several of his papers, because this sort of nonsense gets people killed.

I remember the times when the Hatcher analysis, based on bullet weight, velocity, and a factory for bullet shape, was the Gold Standard in the handgun community. Hatcher's model was simple, based on intuition that momentum meant "stopping power", and the belief was akin to a religion.
 
"...Native Americans, killing bison..." Usually by running 'em off a cliff. Using a bow or spear to kill a buff is incredibly dangerous. Native's couldn't risk losing the people who defended the villages. Arrows were used, primarily, to lay claim to a carcass by an individual. Said arrow having personal markings on it.
Hydrostatic shock isn't what kills anything with anything. Shock, yes, just not the amount of fluid being displaced. The term was invented by gun rag writers to start with.
And it's 500 ft-lbs. that suggests that remote neural effects can occur with levels of energy transfer possible with handguns. No handgun round guarantees any incapacitation though.
Read this.
https://arxiv.org/ftp/arxiv/papers/0803/0803.3051.pdf
 
T. O'Heir, while HS shock does not kill, it can, and DOES, incapacitate by disrupting the neurological system. That reduces the adrenaline dump and provides time for the blood loss to occur leading to proximate death.

About 4x overpressure is, in and of itself, the 50% fatality threshold in humans, but no cartridges we are talking about can deliver that level of pressure wave in a human body.
 
T. O'Heir,

If the Native Americans, killing bison, arrow and spears anology, didn't serve the the context of question just.... This will.

https://m.youtube.com/watch?v=h_oGuUA2hgE

Thanks for the link. However you summed up the "Hydrostatic Shock" theory, in a few lines perfectly. While their thesis, was four pages.

Not to add gas to the fire, for every statement made, there was an opposing statement. God bless Sir Issac. :D.

However, what the consensus here " in this thread," is stating, is One mans opinion, got picked up and folks started rolling with it. We can all agree, 1000 ft/lbs, isn't correct. Many other variable come into play. Whether it be neurological or liquid displacement from vital organs. Be it a massive shock wave, breaking bones or rupturing tissue. An animal that is killed, will always be dead. However done, rifle, shotgun, revolver, canon or F-150. Poundage is a way of putting, more regulations on a heavily regulated sport to begin with. To each state, to provide their own laws. As if to say, this is correct within these imaginary boundaries. Abide or don't come at all.

Thank you everyone, for your comments and thoughts. It has been more than informative and sparked more thought, than I could have imagined.
 
As for the original question:
But if rule of thumb stands, it requires 1000 ft lbs energy, to require hydrostatic shock, wouldn't that eliminate all handgun hunting for deer, ect...
Click to expand...
No, it wouldn't.
The .44 Mag does generally meet or exceed the 1,000 ft-lb threshold from barrels 4" or longer.
As do some or most factory loads for .41 Mag, .454 Casull, .480 Ruger, .475 Linebaugh, .460 S&W, .500 S&W (often in the 2,000+ ft-lb realm), and more.

But most states that regulate such things typically set the limit at 500 ft-lb, not 1,000 ft-lb. And that opens the doors for many, many more cartridges. With full power loadings, even 10mm Auto and .327 Federal will meet the energy minimum. (.327 Federal can do so in a 3" barrel - let alone the more common 4", 5.5", and 7.5" barrels.)

Given that hydrostatic shock really isn't a factor at (typical) handgun velocities, the 'arbitrary' energy requirements are usually just intended to keep lower powered cartridges out of the mix, to reduce the number of wounded and unrecovered animals -- much like the ".23 caliber or larger" and/or "two inches or longer" requirement(s) that used to be so pervasive for rifle cartridges. (Quite often, those regulations were aimed primarily at keeping .22 Hornet, .222/.223/.222M, .22-250, .220 Swift, .25-20, .30 Carbine, and .32-20 out of the mix.)
 
Frankenmauser,

Thanks for stopping by. I stand corrected, as those cartridges do have some/several loadings at or above 1000ft/lbs. But you'll have to forgive me, as they aren't as common. You would somewhat agree, by some standard. Except for the .44 and .41. Which by my quick glance this morning, gave 700+ ft/lbs for the .44. What caught my attention, as the biggest surprise was the 10MM. As I have always understood it to be a pistol, where the others were revolvers. What state/s allow hunters to use pistols? Because by that account, topped with your 500ft/lbs, opens up a much wider market. Such as the .50 Action Express and to other C&R fans, the Tokarev... Also, I read a reloader's magazine, several months back about the .327 Federal. From what I gathered, it wasn't much of a hunter. More of a cowboy throwback. I'll have to check it out again, as I didn't think it had much a$$ at all.
 
Last edited:
There are several methods, rules of thumb etc. to help determine suitability for a particular round to be successful. To a degree all are somewhat accurate.

But at the end of the day a bullet placed in the vitals with enough energy to expand reliably and penetrate enough to reach them is what is needed. There is more than one way to make that happen.

With most rifles and handguns using 20th century bullet technology energy numbers could be a pretty accurate method to determine success. But many old school, large caliber black powder rounds firing heavy bullets would give very good penetration with very low energy numbers. Because of the large caliber expansion is not needed. The same can be said for many handgun loads. And many small fast bullets have very good energy numbers, but give very poor penetration.

In the last 20 years or so bullet construction technology has re-written all of the rules. Most any of these bullets will provide excellent penetration. Even very small fast bullets. With most bullets today I believe the more accurate method is to base the decision on how much penetration a particular load will get in ballistic testing. And the minimum velocity needed to get reliable expansion. If bullet "A" needs a minimum of 1800 fps to expand and if it will get enough penetration to reach vitals then it is acceptable. If the range is long and impact speeds fall below 1800 fps, then that round is not acceptable beyond that range.

Bullet diameter and weight are almost irrelevant anymore. Certainly much less so than years ago. In 2016 a 243 firing a premium 100 gr bullet will outperform a 180 gr 30-06 bullet using technology from the 1930's. Probably even from the 1990's.

Using energy numbers actually did the same thing. Saying you needed 1000 ft lbs of energy actually meant that the bullet needed 1000 ft lbs in order to expand and still reach vitals. I still think it is fairly accurate with bullet technology of the 20th century. It doesn't work as accurately with 19th century bullets or with more modern 21st century bullets.
 
Doctors who are also hunters have looked for evidence of "hydrostatic shock", the transmission of force through the blood vessels to the brain in big game, like the brake system on a car works. They found no resulting brain damage. Tissue damage or disruption of the nervous system as previously mention is what kills.
 
Doctors who are also hunters have looked for evidence of "hydrostatic shock", the transmission of force through the blood vessels to the brain in big game, like the brake system on a car works. They found no resulting brain damage. Tissue damage or disruption of the nervous system as previously mention is what kills.
Click to expand...

That is funny, and wrong on so many levels. First, HS shock has nothing to do with force transmission through the circulatory system. Second, shock waves at low to moderate levels leave absolutely NO evidence that they even occurred. Third, the forensic sciences deal with it, in various forms, on a regular basis. I guess those corpses I have examined with no evidence of trauma did not die from a shock wave.

Hydrostatic shock is not, in and of itself, observable in tissue, at least for man portable firearms. It has a combining effect related to incapacitation that gives more time for the actual mechanisms that DO kill to work.
 
Last edited:
The 1000 ft/lbs number is a manufactured number sold to hunters as the minimum to reliably kill game animals. Oooookaay :rolleyes: . . . so answer me this, how did the settlers 300 years ago almost exterminate deer, elk, moose, antelope, grizzly bears, etc? Most muzzle loaders cannot generate the 600 ft/lbs that used to be touted as the minimum (let alone the current "minimum" 1,000 ft/lbs), so how did the settlers survive? They were good at field craft, and they made sure they put the hole in the right part of the animal. More energy does not guarantee a kill, if it did then everyone would shoot giga-magnums (oh, wait . . .) and never lose an animal.

As stated earlier, blood loss or suffocation kills (or a direct CNS hit), so a major artery/heart hit, or collapse the lungs, or hit the head/spine. I know people who have killed deer with a 25-20. Let that one sink in for a second. Only about 400 ft/lbs. I have personally killed animals with a 38 Special. I have killed a few with a 22 as well. OK, now we're getting pretty far down the energy scale! The point is, shot placement makes up for poor energy, but more energy never makes up for poor shot placement (in spite of Roy Weatherby's statements)! I have killed game animals with 45ACP, 357 Magnum, 44 Magnum, 30-30, 7X57, 7mm Rem Mag, 8mm Rem Mag, 375 H&H. Never had one walk away unless I poked the hole in the wrong place. And in that one case, more energy probably would not have made the difference.

As far as hydrostatic shock, in layman's language that means that the water (tissue fluids) could not get out of the way of the energy wave fast enough, so it bursts/tears the surrounding tissues (like water balloons!!!), creating a wound channel. A pointed bullet needs to be traveling above about 2,000 fps in order to cause hydrostatic shock. Big bullets (think pistol bullets) traveling below that level generally make very neat holes in stuff. Hollow points make messy holes for a variety of reasons, but partly through the same mechanisms.
 
What caught my attention, as the biggest surprise was the 10MM. As I have always understood it to be a pistol, where the others were revolvers. What state/s allow hunters to use pistols? Because by that account, topped with your 500ft/lbs, opens up a much wider market. Such as the .50 Action Express and to other C&R fans, the Tokarev... Also, I read a reloader's magazine, several months back about the .327 Federal. From what I gathered, it wasn't much of a hunter. More of a cowboy throwback. I'll have to check it out again, as I didn't think it had much a$$ at all.
Click to expand...
Nearly all free western states allow handguns - pistol or revolver doesn't matter. Some even have specific season and/or units for "short range weapons" which is intended primarily as a handgun/shotgun hunting season.

There are many states east of the Rockies that allow non-revolver handguns, as well. When I lived in Florida, for example, I was perfectly legal hunting deer with a Taurus .380 Auto. (And under the circumstances, I believed it to be more than adequate for those 40-70 lb deer. ... Still do, for that matter.)

.327 Federal has to truly be interesting to the shooter for it to be worthwhile. For the average shooter, .357 Mag is a better option.
But, I'm not average (above or below depends on your perspective ;)). I have four .327 Federal revolvers in my safe, among the .44s and .480 Ruger. :D
Each cartridge has its place, and I don't feel 'under-gunned' when carrying any of those revolvers (always legal for the season, of course - some states do have caliber restrictions that exclude .327 Federal for Elk and Moose).
 
Not the same as "hydrostatic shock" but there was a study done by the Swedish fish and game people on the effect of the "temporary cavity," sometimes called "stretch" vs "crush". The direct translation was "pulsatile cavern."

They came up with a velocity of 2650 fps for an effective "pulsatile cavern" on European elk (look like a 7/8 scale moose.) Amazing, right in there with the 6.5 Swedish Mauser which has no doubt killed several barge loads of game.
What a coinkydinky, eh?
 
That's why I laugh at all the new 6.5 cartridges .I shot my 6.5x55 for 25 years .One shot , one deer ! Boring. Please remember that both Sweden and Norway used the 6.5 .Norway using the Krag.The two countries finally agreed on dimensions -6.5x55SE. I still believe that the 140 is the best for that cartridge. The comment that Swedes use it for Moose ? Only with the 160 and at certain powerlevels. Finn AAgaard called the 6.5x55 the perfect deer cartridge !! I agree.:D
 
You must log in or register to reply here.
Back
Top