Cosmoline
Member
I'm going to have to track that book down. Sounds interesting!
That's a good quotable.
overpenetration and "expending energy in the target"?
- Thread starter hardheart
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I'm going to have to track that book down. Sounds interesting!
That's a good quotable.
481
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Here you go, man. I hope it saves you some time- http://www.amazon.com/Bullet-Penetr...n-Resulting/dp/0964357712/ref=tmm_hrd_title_0
easyg
Member
This is the first time I've ever heard of such a thing.
Can you elaborate?
And does it only apply to GSWs?
How about stab wounds?
Doc3402
Member
Stab wounds seem to present more external bleeding. One train of thought is that the more ragged wound doesn't cause the blood vessels in the skin to retract. Another train of thought is that a bullet cauterizes the skin vessels as it passes through. I don't know or care which one is right. It happens and it makes a difference in how the patient is treated.
There is very little, if any external bleeding from most single projectile gun shot wounds, but there is some argument about whether the vessels have retracted or been cauterized. You will see some external blood eventually, but by the time that happens the patient is usually in deep shock. The muscles have relaxed and allowed the container to flatten out a little which reduces the internal space.
So much for the easy one. I could spend the next year or so giving you a lesson in human physiology, but I would prefer trying to keep it short with an oversimplified example of a constant volume of fluid in an essentially closed container. Here goes.
Take a plastic water bottle and empty it. Punch two icepick holes in it, one on the side near the bottom, and the other 180 degrees from the first one near the top. Seal both holes with tape and fill the bottle with water. Put the bottle cap back on making sure it's tight.
Now stand the bottle up and remove the tape at the bottom. If the lid is tight and the tape at the top has a good seal you will get very little leakage. Remove the tape at the top and tell me what happens. You can repeat this project as many times as you want with the bottle in any position you can imagine. The results may vary to a very slight degree, but unless you exert outside pressure on the bottle they are essentially the same for our purposes.
I know that some people are sitting there thinking that the human body is not as rigid as the bottle is, and I agree, but the lesson is hydraulics. Without outside influence your muscle tone and skeletal system will maintain the basic shape of the body keeping it a generally fixed capacity vessel with a fixed volume of fluid.
If you think you can do it you can repeat the experiment with a plastic bag. As long as you can come up with something to proportionally duplicate the actions of muscle and bone on the bag the experiment will come out the same. This experiment isn't about body tissue versus plastic. It's about simple hydraulics.
Okay, we covered the exit wound part. Let's move down to the blood vessels. You're either going to have to spend some money or just be happy with picturing this in your mind. Take two closed containers, they can be flexible or not, but flexible is safer. Join the two containers with either a rigid pipe or a flexible tube. Put a closed shut off valve in the pipe and something like a tire valve in one of the containers.
At this point the inside of both containers should be at atmospheric pressure. Pressurize the container with the valve. We'll use this to represent the blood vessels. Two PSI will be enough to show what you need. Open the valve between the two containers and tell me what happens.
The pressure in the first container dropped until the second container was of equal pressure. Now repeat the experiment using colored water and vent both containers to speed things up. What happened? The water equalized until the two containers had equal amounts of water. If you're really feeling adventurous you can repeat this a third time using colored water under pressure. as soon as you open the valve both the water and the pressure will equalize between the two containers.
This is not rocket science. It's simple physics, and it can't be ignored. Can the results be altered? Yes they can. It requires an outside force.
Okay, enough of this. All of this is really immaterial if you can manage to destroy the pump that circulates the fluid within the closed container. Nothing changes about the pressures, nothing changes about the volumes. The only thing that changes is the transport of oxygen. There isn't any. Destroying the pump does not make a DRT situation. For somewhere around 30 seconds or more this person is still capable of thought and motor function.
Okay. one more thing on this over-penetration subject. It doesn't matter. If you will look at gunfight after gunfight after gunfight you will see that way too many of them have something in common. At least one bullet will miss it's target. The target will not expand that bullet and catch it.
Tailoring your ammo to reduce over-penetration is a poor substitute for making sure of what's behind your target. You can check with the NYPD on that one... or the several people shot by police bullets near the Empire State Building.
Since you brought up stab wounds in a gun forum I'm going to add something that is very important for the medical people. It is very helpful to know whether the assailant was male or female.
There is very little, if any external bleeding from most single projectile gun shot wounds, but there is some argument about whether the vessels have retracted or been cauterized. You will see some external blood eventually, but by the time that happens the patient is usually in deep shock. The muscles have relaxed and allowed the container to flatten out a little which reduces the internal space.
So much for the easy one. I could spend the next year or so giving you a lesson in human physiology, but I would prefer trying to keep it short with an oversimplified example of a constant volume of fluid in an essentially closed container. Here goes.
Take a plastic water bottle and empty it. Punch two icepick holes in it, one on the side near the bottom, and the other 180 degrees from the first one near the top. Seal both holes with tape and fill the bottle with water. Put the bottle cap back on making sure it's tight.
Now stand the bottle up and remove the tape at the bottom. If the lid is tight and the tape at the top has a good seal you will get very little leakage. Remove the tape at the top and tell me what happens. You can repeat this project as many times as you want with the bottle in any position you can imagine. The results may vary to a very slight degree, but unless you exert outside pressure on the bottle they are essentially the same for our purposes.
I know that some people are sitting there thinking that the human body is not as rigid as the bottle is, and I agree, but the lesson is hydraulics. Without outside influence your muscle tone and skeletal system will maintain the basic shape of the body keeping it a generally fixed capacity vessel with a fixed volume of fluid.
If you think you can do it you can repeat the experiment with a plastic bag. As long as you can come up with something to proportionally duplicate the actions of muscle and bone on the bag the experiment will come out the same. This experiment isn't about body tissue versus plastic. It's about simple hydraulics.
Okay, we covered the exit wound part. Let's move down to the blood vessels. You're either going to have to spend some money or just be happy with picturing this in your mind. Take two closed containers, they can be flexible or not, but flexible is safer. Join the two containers with either a rigid pipe or a flexible tube. Put a closed shut off valve in the pipe and something like a tire valve in one of the containers.
At this point the inside of both containers should be at atmospheric pressure. Pressurize the container with the valve. We'll use this to represent the blood vessels. Two PSI will be enough to show what you need. Open the valve between the two containers and tell me what happens.
The pressure in the first container dropped until the second container was of equal pressure. Now repeat the experiment using colored water and vent both containers to speed things up. What happened? The water equalized until the two containers had equal amounts of water. If you're really feeling adventurous you can repeat this a third time using colored water under pressure. as soon as you open the valve both the water and the pressure will equalize between the two containers.
This is not rocket science. It's simple physics, and it can't be ignored. Can the results be altered? Yes they can. It requires an outside force.
Okay, enough of this. All of this is really immaterial if you can manage to destroy the pump that circulates the fluid within the closed container. Nothing changes about the pressures, nothing changes about the volumes. The only thing that changes is the transport of oxygen. There isn't any. Destroying the pump does not make a DRT situation. For somewhere around 30 seconds or more this person is still capable of thought and motor function.
Okay. one more thing on this over-penetration subject. It doesn't matter. If you will look at gunfight after gunfight after gunfight you will see that way too many of them have something in common. At least one bullet will miss it's target. The target will not expand that bullet and catch it.
Tailoring your ammo to reduce over-penetration is a poor substitute for making sure of what's behind your target. You can check with the NYPD on that one... or the several people shot by police bullets near the Empire State Building.
Since you brought up stab wounds in a gun forum I'm going to add something that is very important for the medical people. It is very helpful to know whether the assailant was male or female.
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Shawn Dodson
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This is the most relevant and true statement so far. A bullet has to penetrate deeply enough to reach and damage major blood bearing organs or CNS structure.
12" minimum penetration means a bullet will probably have sufficient potential to penetrate deeply enough. More than 18" penetration means the bullet will probably exit the body and waste its potential to create a larger diameter wound - one that might nick open the wall of a major blood vessel that would have been just grazed by a smaller diameter bullet.
14-16" seems to be the sweet spot for penetration performance for well-designed JHP handgun bullets.
Like breathing.
The reason why trauma docs insert a chest tube is to drain blood that is collapsing lungs.
Except for psychological stops (I don't like getting shot so I'll stop), to physiologically stop someone requires significant trauma to the CNS, the breaking of major skeletal support structures or incapacitation from significant blood loss.
At the velocity/energy levels of most handgun cartridges, any tissue damage will come only from direct contact between the bullet and the tissue. So a handgun bullet passing through a blood rich organ will damage the tissue it actually touches as it passes through, and a larger caliber bullet penetrating more deeply will damage more tissue than a smaller caliber bullet penetrating less -- thus causing more rapid blood loss.
But with high velocity/high energy rifle cartridges (generally velocities over 2,000 fps), the temporary wound cavity (hydrostatic shock?) is sufficient to also cause notable tissue damage. Thus at high enough velocities, the bullet can cause damage to tissue near its path, without physical contact.
But in any case, it's tissue damage, disrupting the CNS, breaking important bones, or causing blood loss, that physiologically incapacitates the target -- not "energy dump."
And sometimes unexpected things happen. Remember LAPD Officer Stacy Lim. She was shot in the chest with a .357 Magnum and still ran down her attacker, returned fire, killed him, survived, and ultimately was able to return to duty.
She was off duty and heading home after a softball game and a brief stop at the station to check her work assignment. According to the article I linked to:
At the velocity/energy levels of most handgun cartridges, any tissue damage will come only from direct contact between the bullet and the tissue. So a handgun bullet passing through a blood rich organ will damage the tissue it actually touches as it passes through, and a larger caliber bullet penetrating more deeply will damage more tissue than a smaller caliber bullet penetrating less -- thus causing more rapid blood loss.
But with high velocity/high energy rifle cartridges (generally velocities over 2,000 fps), the temporary wound cavity (hydrostatic shock?) is sufficient to also cause notable tissue damage. Thus at high enough velocities, the bullet can cause damage to tissue near its path, without physical contact.
But in any case, it's tissue damage, disrupting the CNS, breaking important bones, or causing blood loss, that physiologically incapacitates the target -- not "energy dump."
And sometimes unexpected things happen. Remember LAPD Officer Stacy Lim. She was shot in the chest with a .357 Magnum and still ran down her attacker, returned fire, killed him, survived, and ultimately was able to return to duty.
She was off duty and heading home after a softball game and a brief stop at the station to check her work assignment. According to the article I linked to:
481
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Much as with the term "stopping power" and for the same reasons, I am always surprised that the term "energy dump" remains en vogue. I guess some terminology will never die.
Arriving late to this interesting and informative thread. In the pic below is a contrast between 12"-13" of penetration and 19" to 20" of penetration.
Bullet on the right (factory Remington 357mag/125gr SJHP) was fired from from a 6"/M686 with a muzzle velocity of ~1625fps. This highly regarded ammunition meets Remington's advertised MV of 1450fps as chronographed through two 357mag/4" that I have. Remington's design of this bullet allows for it to be pushed at very fast velocities and keep its mass. From another test, the slower 125gr SJHPs fired from 4" barrels, expanded less due to less stress applied to the bullet allowing for basically the same 12"-13" of penetration.
The bullet on the left is a 158gr Winchester JHP that was handloaded to ~1437fps. The sectional density of the 357/158gr correlates to 10mm/200gr while 357/140gr correlates to 10mm/180gr and 45auto/230gr.
At slower velocities than the 6"/125gr, the 158gr JHP bullet received lower stress, expanded less and penetrated to 19"-20".
Changing from an expanding bullet design to a non expanding, higher sectional density design, one can lower the velocity of a 180gr WFN to ~1200s and expect soft tissue penetration to ~45"-46".
I prefer to use the terms crush/stretch cavity to describe wound channels, something I've picked up over the years, because of the mental images created. Adding pictures helps.
In addition to the well regarded 357mag/125gr SJHP above, another example of optimizing bullet expansion/penetration is:
This Ranger T design has an MV in the upper 900s and it hits very hard. In the 12"-13" penetration zone, it has ~2.5 ounce crush cavity, very large for a service caliber.
Flat across expansion is the optimal shape one desires for personal defense. If you look closely, you can see the Winchester star at the center of the bullet, doesn't get any better than this.
Bullet on the right (factory Remington 357mag/125gr SJHP) was fired from from a 6"/M686 with a muzzle velocity of ~1625fps. This highly regarded ammunition meets Remington's advertised MV of 1450fps as chronographed through two 357mag/4" that I have. Remington's design of this bullet allows for it to be pushed at very fast velocities and keep its mass. From another test, the slower 125gr SJHPs fired from 4" barrels, expanded less due to less stress applied to the bullet allowing for basically the same 12"-13" of penetration.
The bullet on the left is a 158gr Winchester JHP that was handloaded to ~1437fps. The sectional density of the 357/158gr correlates to 10mm/200gr while 357/140gr correlates to 10mm/180gr and 45auto/230gr.
At slower velocities than the 6"/125gr, the 158gr JHP bullet received lower stress, expanded less and penetrated to 19"-20".
Changing from an expanding bullet design to a non expanding, higher sectional density design, one can lower the velocity of a 180gr WFN to ~1200s and expect soft tissue penetration to ~45"-46".
I prefer to use the terms crush/stretch cavity to describe wound channels, something I've picked up over the years, because of the mental images created. Adding pictures helps.
In addition to the well regarded 357mag/125gr SJHP above, another example of optimizing bullet expansion/penetration is:
This Ranger T design has an MV in the upper 900s and it hits very hard. In the 12"-13" penetration zone, it has ~2.5 ounce crush cavity, very large for a service caliber.
Flat across expansion is the optimal shape one desires for personal defense. If you look closely, you can see the Winchester star at the center of the bullet, doesn't get any better than this.
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