Modern Data on stopping power

[vanilla_gorilla]

Don't fall into the trap of "idolatry of velocity." Velocity doesn't create a pressure wave. The retarding force creates the pressure wave. It's not about velocity. It's about the local rate of kinetic energy transfer.

No fear of that, sir. It's a .45 caliber 230 grain bullet for me until some absolutely groundbreaking research and extensive proof shows me anything is better. I'm not familiar enough with pressure wave research, but I do know that the penetration and permanent crush cavity of a good .45/230 JHP will do.

I'm one of the last to go for the "velocity does it all" stuff.

 

[mavracer]

In the longer term it might lead to incremental design improvements with new bullets that create a larger peak pressure wave without sacrificing penetration or crush cavity

good luck as this would seam to contradict the laws of physics which is a big part of my problem with your research.with a given load you only have so much energy to transfer if you use it faster to create a larger pressure wave penatration will surely suffer.
but keep trying and if you find a magic bullet that does what you say send them to mike at doubletap he does wonders at sending them downrange.
ps. just printed your papers and HWFE to read I am looking foward to the reads I'll PM ya later if thats ok

 

[Dobe]

I wish I had tuned into this thread earlier. It is informative. Dr. Courtney, how does the wave theory relate to the hydrostatic shock theory offered in the late 70's? If this question has been answered already, I appologize.

 

[Logos]

with a given load you only have so much energy to transfer

That is true.....and some people are attempting to use that energy more efficiently.

I doubt that we have yet come very close to the optimum levels that can be attained......but we are clearly getting better.

 

[Michael Courtney]

good luck as this would seam to contradict the laws of physics which is a big part of my problem with your research.with a given load you only have so much energy to transfer if you use it faster to create a larger pressure wave penatration will surely suffer.

From time to time, there are suggestions in the wound ballistics literature that violate the laws of Physics, but I don't think you'll find any in our papers. (We both have PhD's in Physics.)

The origin of the pressure wave is the retarding force between the bullet and tissue. This does depend on the local rate of energy loss by the bullet, which means that the bullet must have energy to lose. However, this energy can be used to create a bigger pressure wave by not wasting too much energy early in the wound channel with pre-mature expansion. Suppose a brilliant eneineer can design a bullet which delays penetration for 4" or so (so it penetrates with little resistance) and then expands to a larger than normal diameter (say 1") before eroding back down to a normal size and continuing to penetrate to the desired depth. To be sure, the design is tricky, but it would use the same energy to create a larger peak pressure wave.

Alternatively, the laws of Physics don't demand that all the energy of the pressure wave come from the kinetic energy of the bullet. There may be governmental laws, engineering challenges, impractical cost, and political obstacles against chemically enhancing the pressure wave, but there is no law of Physics against it.

but keep trying and if you find a magic bullet that does what you say send them to mike at doubletap he does wonders at sending them downrange. ps. just printed your papers and HWFE to read I am looking foward to the reads I'll PM ya later if thats ok

Not trying for a magic bullet, just incremental improvements and sound science.

Michael Courtney

 

[Michael Courtney]

I wish I had tuned into this thread earlier. It is informative. Dr. Courtney, how does the wave theory relate to the hydrostatic shock theory offered in the late 70's? If this question has been answered already, I appologize.

The Wikipedia page on hydrostatic shock has been updated to reflect the relationship:

http://en.wikipedia.org/wiki/Hydrostatic_shock

Thanks,

Michael Courtney

 

[Dobe]

Without attempting to be challenging, how would you compare this theory to yours?

Wouldn't shock waves travel easier via a liquid medium?

 

[Dobe]

I personally believe in the theory (or some type of wave therory) myself. How else could one explain the devestation of a 150 gr. 30/06 traveling approximately 2700 fps as compared to a 230 gr .45 acp?

 

[Logos]

It's obviously (whether you call it "wave theory" or something else) a fact.

Hunters have known this for as long as high-velocity loads have been available.

You can shoot a deer in the neck and have it drop like a sack of potatoes--and get up a minute later and run off without serious injury if no major blood vessels have been hit.

For many years I have used the "high lung shot" on deer, a shot that always drops them in their tracks to stay--because it passes close enough to the spine to stun the deer and the bleeding incapacitates them before they sufficiently recover......meaning they die right where they fall.

The neck shot is not nearly as sure.....because if you hit ABOVE the spine the deer will get up and run away unexpectedly.....and often escape to survive quite well because the damage is actually minimal.

If you happen to BREAK the spine.....the deer is dead.

If you hit BELOW the spine.....you will almost always blow out so much important stuff that the deer will die where it falls before it has time to recover.

But the neck is a chancy target and the high lung shot is the best.

 

[Logos]

BTW......rifle shooters may remember--we went through all this many years ago.

Then it was called "Hydraulic Transmitted Shock" and was the pet theory of some high velocity freaks.

They mistakenly thought the effect came from a wave of blood that slammed into the brain of the animal.

This is noted in Jack O'Connor's book, "The Hunting Rifle."

O'Connor, BTW, did not believe this theory, and said so.

He thought that the sometimes sudden death was simply the result of the massive bleeding that often occurred in wounds from high velocity bullets.

 

[Dobe]

My memories from the theory of hydrostatic shock is a two fold theory, some of which I too have seen from downed deer.

From a solid hit of a 130 gr .270 or a 150 gr 30/06, it is not uncommon to see an entry wound the size of the caliber, and the exit would measure in inches. I believe that the theory of hydrostatic shock explains this as the compression of fluids ( and of course solid debris) ahead of the moving bullet.

The other portion of the hydrostatic shock theroy rides on the coat tail of the former. It is the compression of liquids in the body under a "hit" from a very fast projectile, which forces fluids in all directions of the wound canal; the force diagram doesn't only point ahead of the bullet. This means that a blood vessel, or simply body tissue, pierced by that 30/06 would force blood and fluids back to the brain and other parts of the body under this pressure.

This is the way I understand it. By no means am I a scientist, and that is my disclaimer. Now I am trying to understand how the wave theory differs. I read the Wekipedia explaination, but I am still not sure.

 

[Logos]

I personally incline toward the idea that there is a neurological shock to the brain that is caused by the "wave" creating shock and pain to nerves in the wound area, and the massive surge of feedback temporarily short-circuits the brain......an electrical event more than a physical event.

Since the spine is the biggest and most sensitive mega-nerve we have......the more explosive high-velocity wounds close to the spine cause the most dramatic results.

That shock is sometimes powerful enough to put man or animal on the deck unconscious, sometimes disorienting, and.....depending on the state of mind of the target....sometimes does nothing.

A man on drugs or a deer that is thoroughly terrified can take a lot of punishment and keep on going.

 

[Dobe]

Sound reasonable. Nevertheless, neither hydrostatic shock to the brain nor neurological shock as you have defined can be depended on 100 % of the time. Since you are a deer hunter too, I am sure that you have seen whitetail run for hudreds of yards with their heart shot out. Therefore, although I enjoy the infomations on this thread, for pistol velocities I will still prefer the .45 ACP with a 230 gr projectile.

 

[Logos]

Nothing can be depended upon 100 percent of the time--although head shots are pretty darn reliable.

With more and more bad guys wearing bullet-proof clothing......maybe a hail of .22 bullets to the head is the way to go.

 

[mavracer]

A man on drugs or a deer that is thoroughly terrified can take a lot of punishment and keep on going

+1 on that shoot a wild boar that been run by dogs sometime,talk about absorbing punishment.