Home Forums Hunting & Shooting Ask The Gunwriters Hydrostatic Shock

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.

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".

A pressure wave is a more precise description. It's a sudden increase in pressure in the tissue, not just the water content of the tissue, and this pressure increase propagates through the tissue. Direct applied force and momentum transfer are redundant, as force is equal to the rate of momentum transfer, but I agree that the wound channel is determined by the amount of applied force and the extent to which that force propagates through the tissue as a pressure wave.

Momentum is mass x velocity, whereas kinetic energy uses the square of velocity.

Seems to me killing power is a rather complicated mix of forces.

DF

Momentum = mv
Net force = ma

So force is equal to the time derivative of momentum, or in other words, the time rate of change of momentum.

Quit........when you are behind!

My 3 year old grandson has greater application skills.

When you find yourself in a hole....

STOP digging.


Jerry

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.

JMHO

Jordan, I'm glad you're still here.

I'm sincere ! FIRST - I have no doubt the hi level math jargon you have used IS correct.

I don't have to tell you or mathman that I have NOT studied above Alg I II and Geometry. I did not take
trig or calculus......

So many of the terms y'all have used are ABOVE my head....I suspect others don't understand too.

IF we don't understand your terminology in real life then how are we supposed to apply it to the killing "mechanics"
of hunting ? NO criticism nor sarcasm. For Real.

I'm familiar with a FEW terms y'all have used but in hunting....??..I can't understand how they apply to
FLESH, BLOOD, & BONES -- not yelling just emphasis.


WE all have heard of "apples vs oranges" -------> that's how I see (understand) the comparisons using
sand, wood, dirt, --- vs Animals (flesh, blood, bones, hide).
I honestly don't see how an accurate comparative result can be had.


Now, (honestly) when you, mathman, a surgeon, or astrologer talk OVER our heads-- we don't understand.
No criticism.

I have dealt with people who don't understand auto mechanics or maintainance and they don't understand the terminology.


It's not that I think you are wrong on all of this....I can't see how you can deduce the amount of force used, transferred, or
wasted on an animal.

The mediums are SO diff it doesn't make sense how the math formulas (formuli) really apply.

That's the best I can describe it and I don't want to EXTEND my math level. LOL

No Harm, No Foul

Jerry

I need a .378 Weatherby.

Naw, Naw Gib, I have a 'mere' 8mm (323) Rem Mag and deer disappear at the thot of that thing!


Jerry