Hydrostatic shock is real. The real question is, in a particular kill is, was it achieved, and how much of an affect in killing the animal did it have?
HS isn't magic, doesn't cause damage at extreme distances from the bullet's path (except for unusually favorable conditions), and a bullet must still be placed somewhere in, or close to, the vitals for HS to kill. Killing by the traditional temporary and permanent wound channel mechanics is still just as good as ever, HS is just frosting on the cake for those who load to achieve it. The benefits of HS, when achieved are: 1) a little more room for aiming error; 2) the animal dies quickly with no tracking required; and 3) there is no bitter-tasting adrenaline pumped into the muscle tissue while the animal attempts to run off.
For HS to have an affect, muzzle velocity must be upwards of 3500fps or above (and the bullet still has comparatively high velocity when it hits the target), and the terminal shape of the bullet includes a flat front profile to launch the HS pressure wave into the tissue. Conversely, a bullet that "mushrooms nicely" launched at sub-3500 velocities won't produce HS. In other words, there are relatively few hunting cartridges with the velocity potential to achieve HS, and even then, the user must produce his own handloads tailored for the extreme upper end of the velocity window, and then must use one of the few bullets with a flat terminal profile. Hardly anyone does this, which is why so many people say HS is not real.
I cannot explain any of this in scientific terms. Take a look at a bullet's effect on gelatin. Even a solid damages gel beyond its diameter. I have no idea what you might call the forces that cause the damage, but that damage has incapacitation value. That stands to reason. I suspect that's what people mean when they use the term hydrostatic shock. There is a relationship between the bullet's construction and the amount of damage beyond that damage imparted by the bullet proper and the pieces of the bullet. Let me just throw another term out here to touch on the value of that damage. Bloodshot meat. Likewise there is a relationship between a bullet's construction and penetration.
Spectacular DRT kills seem to happen more often with bullets that expand violently and shed their weight, provided that the bullet penetrates sufficiently to reach the organs that contain a lot of blood. There are always anomalies. I have peeled deer that DRT and seen heart damage that was very similar to deer that ran a 40 yard death dash. Deer are individuals and will have individual reactions to the damage.
It's fun to dabble in differences over what to call the various scientific factors at play, but none of the terms, or misuse of the terms, changes the science. Bullets damage beyond their diameter. Bullets need to penetrate deeply enough to damage the organs that pump a lot of blood. There are a lot of bullets that hit that sweet spot and a lot of velocities at which they hit that sweet spot.
You also might shoot more bullets into various kinds of test media.
I'm in total agreement bullets definitely cavitate
As I said in a previous post after thinking about it a bit, I don’t dispute that inertial cavitation may occur at the pressure front of a bullet moving fast enough, I just have a hard time believing that the heat and acoustic shockwaves associated with the collapse phase of cavitation contributes significantly to the damage done by the bullet. I could see it producing some of what we call “bloodshot” tissue. But again, I may be wrong about that. The question is not whether or not cavitation takes place, but what causes the damage to the tissue that we observe when shooting a critter with a rifle bullet.
To be clear, I’m making a distinction between the pressure wave that pushes tissue away from the bullet’s path, and the cavitation (vaporization, collapse of cavity, and resulting shockwave/heat) of fluid immediately in front of the bullet.
You also might shoot more bullets into various kinds of test media.
I'm in total agreement bullets definitely cavitate
As I said in a previous post after thinking about it a bit, I don’t dispute that inertial cavitation may occur at the pressure front of a bullet moving fast enough, I just have a hard time believing that the heat and acoustic shockwaves associated with the collapse phase of cavitation contributes significantly to the damage done by the bullet. I could see it producing some of what we call “bloodshot” tissue. But again, I may be wrong about that.
To be clear, I’m making a distinction between the pressure wave that pushes tissue away from the bullet’s path, and the cavitation (vaporization, collapse of cavity, and resulting shockwave/heat) of fluid immediately in front of the bullet.
With enough hydraulic pressure the tissue is stretched beyond its elasticity and creates a large wound channel. The larger the animal the less effects of the hydraulic pressure
I got banned on another web site for a debate that happened on this site. That's a first
You also might shoot more bullets into various kinds of test media.
I'm in total agreement bullets definitely cavitate
As I said in a previous post after thinking about it a bit, I don’t dispute that inertial cavitation may occur at the pressure front of a bullet moving fast enough, I just have a hard time believing that the heat and acoustic shockwaves associated with the collapse phase of cavitation contributes significantly to the damage done by the bullet. I could see it producing some of what we call “bloodshot” tissue. But again, I may be wrong about that.
To be clear, I’m making a distinction between the pressure wave that pushes tissue away from the bullet’s path, and the cavitation (vaporization, collapse of cavity, and resulting shockwave/heat) of fluid immediately in front of the bullet.
With enough hydraulic pressure the tissue is stretched beyond its elasticity and creates a large wound channel. The larger the animal the less effects of the hydraulic pressure
I agree, but cavitation describes more than just hydraulic pressure.
You also might shoot more bullets into various kinds of test media.
I'm in total agreement bullets definitely cavitate
As I said in a previous post after thinking about it a bit, I don’t dispute that inertial cavitation may occur at the pressure front of a bullet moving fast enough, I just have a hard time believing that the heat and acoustic shockwaves associated with the collapse phase of cavitation contributes significantly to the damage done by the bullet. I could see it producing some of what we call “bloodshot” tissue. But again, I may be wrong about that.
To be clear, I’m making a distinction between the pressure wave that pushes tissue away from the bullet’s path, and the cavitation (vaporization, collapse of cavity, and resulting shockwave/heat) of fluid immediately in front of the bullet.
With enough hydraulic pressure the tissue is stretched beyond its elasticity and creates a large wound channel. The larger the animal the less effects of the hydraulic pressure
I agree, but cavitation describes more than just hydraulic pressure.
They definitely cavitate, it can be seen in high speed videos. I'm a bit confused on your position.
I got banned on another web site for a debate that happened on this site. That's a first
Jordan, I’ve been reading Hunting, Shooting rags and books since the early 70s. I’ve never heard of “secondary fragmentation” applied to flesh, blood, & bones ? ? ?
Jerry
Just because you haven't heard of it, that doesn't mean it doesn't exist.
I didn’t say it did NOT exist.... I never heard it applied to flesh, blood, & bones.
Jerry
Jerry,
I’ve seen the term used commonly in reference to bone fragments, etc., but I admit I may have used the term “secondary fragmentation” a little bit liberally when I included the blood and soft tissue that is rapidly pushed away from the bullet’s path (though I still think it’s not incorrect to do so, arguably).
Well, if you want a long thread, start one on wounding dynamics......
When a bullet strikes flesh, two things happen. A permanent wound channel is created, and so also is a temporary channel.
The permanent channel is formed by crushing and tearing the tissue ahead of the bullet. The temporary channel is formed by elastically stretching and bruising the tissue around the permanent channel (bloodshot). The balance between the two channels depends on the speed of the bullet. Big, slow bullets expend most of their energy on the permanent channel, and little fast bullets are balanced more toward the temporary channel.
The force trying to stop a bullet in flesh is the pressure exerted against the flesh times frontal area. Force is equal to change of momentum. The bullet comes to rest when it has shed so much momentum that it can no longer exert a crushing level of pressure on the tissue ahead of it.
The question in my mind is whether it is correct to call the temporary wound channel the result of cavitation. Yes, the bullet is moving through a gaseous cavity created by stretching tissue. But that seems to me to be the opposite of cavitation. Cavitation happens when something like a propeller creates an area of very low pressure that causes the liquid to vaporize (boil) in little bubbles. That doesn't seem to me to describe the temporary wound cavity. But I'm not done thinking about the issue.
You also might shoot more bullets into various kinds of test media.
I'm in total agreement bullets definitely cavitate
As I said in a previous post after thinking about it a bit, I don’t dispute that inertial cavitation may occur at the pressure front of a bullet moving fast enough, I just have a hard time believing that the heat and acoustic shockwaves associated with the collapse phase of cavitation contributes significantly to the damage done by the bullet. I could see it producing some of what we call “bloodshot” tissue. But again, I may be wrong about that.
To be clear, I’m making a distinction between the pressure wave that pushes tissue away from the bullet’s path, and the cavitation (vaporization, collapse of cavity, and resulting shockwave/heat) of fluid immediately in front of the bullet.
With enough hydraulic pressure the tissue is stretched beyond its elasticity and creates a large wound channel. The larger the animal the less effects of the hydraulic pressure
I agree, but cavitation describes more than just hydraulic pressure.
They definitely cavitate, it can be seen in high speed videos. I'm a bit confused on your position.
Yes, I’ve seen such videos in the past. This thread was about the mechanisms that cause tissue damage, not the mechanics of the process of the bullet traversing through an animal. My position is this: I believe that the damage is done mainly by mechanisms other than the shockwave/heat resulting from cavitation. Would you agree that the wound channel is caused by the pressure wave produced by the bullet?
Here’s an illustration of cavitation. I saw this video a year or two ago.
I think Mule Deer has a most excellent grasp of how bullets work and how to use them.
Animals contain a lot of fluid, central nervous system insult can cause a profound collapse, the rumen can be full and turgid and other times loose and flaccid. So can the lung field.
Kinetic energy in my mind is an important element in the indice of a bullet cartridge capabilities. They wouldn’t be called a kinetic ordinance if it wasn’t an element to monitor.
Bottom line ………..
to para phrase Elmer Keith:
If you think you are close enough…….
Get closer.
Last edited by Angus1895; 09/02/21.
"Shoot low sheriff, I think he's riding a shetland!" B. Wills
Kinetic energy in my mind is an important element in the indice of a bullet cartridge capabilities. They wouldn’t be called a kinetic ordinance if it wasn’t an element to monitor.
Well, it is the very basis of being able to do "work."
I think you are calling hydraulic pressure a pressure wave. Either way that is a part of the of the case of the wound channel the other part is the amount of direct crushed tissue. The factors that create a wound channel are the amount of direct applied force, the amount of momentum transfered, the amount hydraulic pressure.
I got banned on another web site for a debate that happened on this site. That's a first
I'm not exactly sure of what I was seeing one time when I shot a snowshoe hare with my .308 with a 180 grain Remington round nose Core-Lokt. The range was maybe 30 yards and at the shot there were bunny parts everywhere, even hanging in the bushes nearby. I'd shot a lot of deer with that bullet and it always worked well, but not overly well like on that four pound hare. I surmise that the same kind of trauma was happening inside of a deer, but that it's larger mass was able to contain the temporary cavity where as the smaller frame of the hare was not. I wouldn't have thought that a 180 grain bullet would expand much in a rabbit size target.
My other auto is a .45
The bitterness of poor quality is remembered long after the sweetness of low price has faded from memory
Hydrostatic shock is the controversial concept that a penetrating projectile (such as a bullet) can produce a pressure wave that causes "remote neural damage", "subtle damage in neural tissues" and/or "rapid incapacitating effects" in living targets. It has also been suggested that pressure wave effects can cause indirect bone fractures at a distance from the projectile path, although it was later demonstrated that indirect bone fractures are caused by temporary cavity effects (strain placed on the bone by the radial tissue displacement produced by the temporary cavity formation).
Proponents of the concept argue that hydrostatic shock can produce remote neural damage and produce incapacitation more quickly than blood loss effects. In arguments about the differences in stopping power between calibers and between cartridge models, proponents of cartridges that are "light and fast" (such as the 9×19mm Parabellum) versus cartridges that are "slow and heavy" (such as the .45 ACP) often refer to this phenomenon.
Martin Fackler has argued that sonic pressure waves do not cause tissue disruption and that temporary cavity formation is the actual cause of tissue disruption mistakenly ascribed to sonic pressure waves. One review noted that strong opinion divided papers on whether the pressure wave contributes to wound injury. It ultimately concluded that no "conclusive evidence could be found for permanent pathological effects produced by the pressure wave".
Hydrostatic shock is the controversial concept that a penetrating projectile (such as a bullet) can produce a pressure wave that causes "remote neural damage", "subtle damage in neural tissues" and/or "rapid incapacitating effects" in living targets. It has also been suggested that pressure wave effects can cause indirect bone fractures at a distance from the projectile path, although it was later demonstrated that indirect bone fractures are caused by temporary cavity effects (strain placed on the bone by the radial tissue displacement produced by the temporary cavity formation).
Proponents of the concept argue that hydrostatic shock can produce remote neural damage and produce incapacitation more quickly than blood loss effects. In arguments about the differences in stopping power between calibers and between cartridge models, proponents of cartridges that are "light and fast" (such as the 9×19mm Parabellum) versus cartridges that are "slow and heavy" (such as the .45 ACP) often refer to this phenomenon.
Martin Fackler has argued that sonic pressure waves do not cause tissue disruption and that temporary cavity formation is the actual cause of tissue disruption mistakenly ascribed to sonic pressure waves. One review noted that strong opinion divided papers on whether the pressure wave contributes to wound injury. It ultimately concluded that no "conclusive evidence could be found for permanent pathological effects produced by the pressure wave".
+1.......
I got banned on another web site for a debate that happened on this site. That's a first
I am now retired, and these are my credentials: - Mechanical Engineering, MS - Agronomy, BS
I find this thread...... amusing.
What is noteworthy is that terminal ballistics, as it relates to tissue damage, lacks a generally accepted Body Of Knowledge. I find here an interesting meld of fluid mechanics, mechanics of materials, kinetics, zoology, anatomy, and good ol' wisdom gained through experience in the field.
