Velocity and Muzzle Energy vs Incapacitation

[entropy]

Ad Hominem.

 

[CraigC]

Firstly, foot pounds don't count for jack spit. It exaggerates the role of velocity and trivializes bullet weight while ignoring diameter.

Forget about hydro-static shock and where t his magical threshold may or may not lie. All else being equal, even with solids, higher velocity causes greater tissue damage. It's not a huge difference and there are zero guarantees but a bullet that stays together and penetrates but hits 200 or 400fps higher velocity is going to destroy more tissue. That is a given. For any given shot, it may or may not result in a quicker end to the threat. It may make no difference, it may make all the difference. There are myriad variables and every shot is a law unto itself. All you can do is improve your odds.

Foot pounds of energy may not be the best standard but it's better than no standard at all.

No it ain't. A bad one is worse than none at all.

What wounding mechanism should we be using?

The problem is that terminal ballistics is terribly complicated and every shot fired carries with it its own rules but people want a simple answer. There ain't one.

 

[Double Naught Spy]

Foot pounds of energy may not be the best standard but it's better than no standard at all.

This is a bit of a false dichotomy without a proof. The GIGO issue still remains. If the standard is wrong, then what good is the standard?

You have to ask. What is ft/lbs telling you? Does it tell you the volume of tissue damaged? Does it tell you about penetration depth? How many ft/lbs will deliver a kill?

Think about it for a second. What do ft lbs tell you as it has to do with terminal performance. You could say, "That is how much energy the bullet is carrying..." and I would ask you what that means, once again, relative to terminal performance.

Yes, higher energy bullets should do more damage than lower energy bullets, ALL OTHER FACTORS being equal, which they virtually never are. However, is this a 1:1 relationship or just a vaguely general trend?

What wounding mechanism should we be using?

While I disagree with Dodson over what energy can do, the problem with energy as a wounding mechanism, even according to the proponents of it, would be that it is not consistent in any form or fashion yet determined. Part of the frustration of the process is that you can shoot two of the same animal in the same approximate location with the same gun/caliber/bullet from the same distance and not get the same terminal results. The bullets may penetrate different depths. They bullets may cause different levels of tissue damage.

So you can use energy as a standard, but is it really telling you more than velocity? Caliber? Bullet weight? Think about it for a second. Do any of those, or Taylor's KO Index or the other calculations provide anything resembling consistent data that can tell you about the wound before you examine it? No. At best they give you generalities that are sometimes wrong.

Earl has his own system. His standard is "decisive bone breakage."

Having a gun and cartridge that is able to decisively break bones can increase stopping power even if nobody believes in stopping power

I would argue that his standard is no more valid and no more invalid than ft lbs. It would sort of seem to follow that breaking more bones decisively would equate with more ft lbs, but does it? Who knows? What is breaking bones 'decisively?' I know for a fact that a .22 lr will break any bone in the human body...but then again, there are different types of bone breakage and that will stem, in part, from whether you are hitting cortical bone, cancellous bone, or a combination thereof. For example, people like to talk about using handguns to 'stop' attackers by shooting them in the hip where upon the hip is invariably described as "shattered." That will depend hugely where the pelvis is struck and if you happen to strike the iliac blade (largest portion of the innominate, of which you have 2) on a human with a handgun round, the iliac blade in humans being mostly cancellous bone, the bullets often can just punch through without shattering and even without pelvic collapse.

---------------------------

What must be kept in mind when using or assigning standards of lethality to bullets is that every shot you take is unique. Part of the reason why all of the current attempts at standards don't work is for the same reason you can't reliably pic a winner of the Indy 500 based on who has the fastest car (pole position) or who has the most horsepower, or make of the engine. That is data about the car and not data about the race. What things like ft lbs or Taylor's KO index fail to take into account is the animal being shot. They are all about the bullet but the bullet is nothing in this consideration without the target when it comes to terminal performance.

So getting back to the OP...

When it comes to defensive carry against humans, does velocity and muzzle energy really matter?

If you are going to focus on energy, then muzzle energy is the wrong end of energy on which to focus unless you are making contact shots. Muzzle energy tells you what is happening at the muzzle of the gun, but does not tell you about down range. With distance, velocity and energy drop, right? So muzzle energy (except for contact shots) is pretty meaningless as you need to know the impact energy. Depending on the make and model of your defensive ammo, some have somewhat narrow performance windows for expansion. Their expansion performance will change with distance. Are you shooting at typical self defense distances inside 10 feet or longer? Maybe you are in Pearl Trailer Park in rural Texas shooting 165 feet. https://www.khou.com/article/news/a...uspect-in-trailer-park-standoff/285-339680509 Maybe you are an Austin mounted cop taking out a gunman at over 100 yards with your pistol. https://bja.ojp.gov/program/badgeofbravery/recipients/2014/adam-johnson So using muzzle energy to predict lethality would be about like determining your travel time based on your speed when you left the driveway of your home. That won't tell you travel time because you haven't included the relevant destination data. I understand this will an unknown until the time of your shooting, but you can work out with a chronograph or a ballistic calculator what the energy will be at given distances and so you can have some idea of impact energy, but you will still be missing the critical target information and you need target information because that is where all the good stuff will hopefully happen. Bottom line, muzzle energy won't work for a lot of reasons.

 

[Zarthab]

Anything from 380 on up with a good hollow point will do. If its worth shooting once its worth atleast 3 times. Shot placement is key, pelvis, face or heart...

 

[JohnKSa]

These tissues aren't blood distribution organs, like the heart and major vessels, and during sympathetic nervous system activation ("flight or flight" response), the blood supply to these organs is reduced. They'll bleed, but they don't bleed in rate and quantity to produce rapid incapacitation like a hole in the heart or a major vessel bleeds.

The original comment was that "vital organs" couldn't be damaged by temporary stretch cavity, not that "blood distribution organs" couldn't be damaged by temporary stretch cavity. Also, it's worth noting that sometimes incapacitation can be induced by trauma to organs even without blood loss. Anyone who has watched enough professional fighting sports has seen a competitor incapacitated by blunt trauma to the liver.

Energy isn't a mechanism of incapacitation.

Well, sorta. It's one small piece of the puzzle. It's certainly not the answer, but it can't be completely left out of the equation either. It would be more accurate to say it is not THE mechanism of incapacitation.

The problem is that terminal ballistics is terribly complicated and every shot fired carries with it its own rules but people want a simple answer. There ain't one.

Yup.

 

[MarshallDodge]

This is the problem with the gun community. We find this trivial thing to argue over when there are far more important aspects of a defensive shooting.

Let it go already.

 

[JohnKSa]

This is the problem with the gun community. We find this trivial thing to argue over when there are far more important aspects of a defensive shooting.

People like to think you can buy stopping power in boxes of 20 or 50, so it's hard for them to let go of the idea that caliber choice out of the service pistol performance class will be a game changer on the street.

Stopping power comes from training and practice, not from the numbers stamped on a firearm.

 

[mavracer]

1) Sonic pressure wave - which is nothing more than the sound wave of bullet impact traveling at ~4000 fps through water-filled soft tissues. It is benign and doesn't damage soft tissues.

Hydrostatic, and yes it won't damage soft tissue in the classic sense, many studies show that it can effect CNS.

2) Temporary cavity - measured at about 60 psi for centerfire rifle bullets that produce a volleyball-sized temporary cavity.

That would be hydrodynamics like I said fluid in motion.

Bruising.

The temporary cavity produces blunt trauma-type tissue injury.

That only addresses 1/3 of my post. How do you measure the line between the two in soft tissue?
And if you use the common definition how do you explain the drastic different wound profiles of my example?

 

[mavracer]

Stopping power comes from training and practice, not from the numbers stamped on a firearm.

I agree 1000% that training and ability are way more important, but the numbers stamped on the firearm is the only other thing that is under your control.

 

[JohnKSa]

Under your control, yes. The problem is that nobody seems to be able to prove that it makes a difference in the outcomes of real-world shootings. The good thing is that you can pick what you want out of the service pistol performance class and no one can prove that you've made a bad choice. The bad thing is that you can pick what you want out of the service pistol performance class and you can't prove your choice will give you an advantage.

 

[jmorris]

When it comes to defensive carry against humans, does velocity and muzzle energy really matter? If a human is hit with a, just for sake of argument:

I have never tested with humans but I have killed hundreds of pigs with the .22lr. Put in just the right spot, it's a "lights out" situation, put somewhere else and you will need either time or another shot.

Almost all of them have been at very close range and I could wait until they allowed me the perfect shot.



I have done it out to 88 yards before though, without a single step after impact. That guy on the other side of the pond, dropped with 1 40 grain standard velocity solid.



That said, more velocity and energy can make up for less than ideal hits, probably why no one in their right mind would suggest a .22lr for hunting pigs. The ability to poke more holes or break more things inside helps destroy the animal.

Do you have to have a lot of velocity and energy to kill something? No. Does it help? It can. Have I ever killed anything too dead? No. Makes me lean towards power and energy as long as that doesn't limit my ability to place it with accuracy.

If each round expands and penetrates to similar dimensions, is there any real world advantage to incapacitating and doing damage to a threat?

Absolutely, take a pin full of animals and start shooting them with your 3 choices. By the time they are all dead, you will understand just how important shot placement really is. Lots of places may not be deadly for quite some time, even if the rounds happened to expand and penetrate to the same size and depth.

 

[BreechFace]

Anything from 380 on up with a good hollow point will do. If its worth shooting once its worth atleast 3 times. Shot placement is key, pelvis, face or heart...

You have more confidence in a 380ACP HP than I do. Many offerings of 380 leave a lot to be desired on penetration.

The ability for a round to penetrate is a variable that should not be ignored for self defense.

 

[Shawn Dodson]

Hydrostatic, and yes it won't damage soft tissue in the classic sense, many studies show that it can effect CNS.

I'm aware of several of those studies, and many have been discredited (not "disproved" because in order to disprove something it must first be "proved"), such as Ann Marie Goransson's study in which anesthetized pigs were shot while hooked up to an EEG; and Dr. Dennis Tobin's theory that energy transfer causes the reticular activating system in the brain to shutdown.

 

[Shawn Dodson]

That only addresses 1/3 of my post. How do you measure the line between the two in soft tissue?
And if you use the common definition how do you explain the drastic different wound profiles of my example?

What wound profiles?

 

[Double Naught Spy]

This is the problem with the gun community. We find this trivial thing to argue over when there are far more important aspects of a defensive shooting.

Let it go already.

You are probably thinking about aspects like training. No doubt training can be hugely helpful and even a determining factor in a fight, but the fight doesn't care about what you or I think is important.

The thing about a defensive shootings, like like our discussion here, is that there are many components to the overall process and you really don't know what all is more important in real time in your particular defensive situation. Going back to my racing example, what is more important in Indy car racing, the engine or the front wing to create proper down force? Obviously, the engine is more important. You can't finish a race without it. Why waste time taking about the front wing? Funny thing, very few Indy cars win a win or place very well with a missing wing and they work to have spares on hand to replace a damaged or lost front wing. What is MOST important is that small bit of trivial consideration that may lose the fight for you. You lose a race and you return next week. You lose a gunfight and maybe you don't return at all. In short, anything that may lose a lethal force fight for you isn't less important than anything else that may lose the fight for you.

Somebody will argue, "But yeah, what are the chances ammo choice will influence your survivability?" Well, that would be a population statistics consideration and you won't be in a population statistics situation. Once you are in a gun fight, you are already in the tail of the statistical curve. Literally, billions of people right now are not involved in gunfights, but that doesn't matter if you are one of the people who are involved in a gunfight right now. Right?

So now and here are perfect places to be discussing the minutia of what may go into fights. We do discuss the other aspects as well, but in this thread, ammo choice is the topic at hand.

Then again, when you think about is, terminal performance is often absolutely critical to the outcome of a fight. That is the business end of ballistics.

 

[Shawn Dodson]

The original comment was that "vital organs" couldn't be damaged by temporary stretch cavity, not that "blood distribution organs" couldn't be damaged by temporary stretch cavity. Also, it's worth noting that sometimes incapacitation can be induced by trauma to organs even without blood loss. Anyone who has watched enough professional fighting sports has seen a competitor incapacitated by blunt trauma to the liver.

The "vitals" we're trying to put a hole in when we shoot a deadly aggressor in the torso, are the heart, major vessels, and upper spinal cord. Yes, there are other vital organs. These other vital organs don't matter when you're trying to quickly stop someone.

When we talk "vitals" in the torso we mean the heart, major vessels, and upper spinal cord. They're elastic.

Ever had the "wind knocked out of you"?

A powerful punch to the abdomen can displace organs in the abdomen, causing them to strain the diaphragm muscle between the abdominal and thoracic cavities of the torso. The strain causes the diaphragm muscle to suddenly contract and spasm, sometimes very painfully, and it can cause people to fall down in psychological reaction to the distress. It can also cause emotional fainting.

Well, sorta. It's one small piece of the puzzle. It's certainly not the answer, but it can't be completely left out of the equation either. It would be more accurate to say it is not THE mechanism of incapacitation.Yup.

A broadhead hunting arrow possesses less kinetic energy than a .22 LR bullet.

What you hit is more important than what you hit with.

 

[Zarthab]

You have more confidence in a 380ACP HP than I do. Many offerings of 380 leave a lot to be desired on penetration.

The ability for a round to penetrate is a variable that should not be ignored for self defense.

I dont have a 380 but there are many that like a pocket gun.
As it has been said, quantity and quality of the hits is what you need.
The goal is to stop the threat as soon as possible, whatever the longer term effects.
Years ago I found these videos for lots of HP tests in various size and caliber pistols.
This one has some good thoughts on penetration and at the end what brands had the best penetration in a 380 micro.

Ammo Quest .380: Federal HST tested in ballistic gel

Thirty-sixth in a series of a quest to find the overall best ammunition for modern micro-compact 380 ACP pistols (such as the Taurus TCP 738, the Ruger LCP, ...

www.youtube.com

 

[mavracer]

What wound profiles?

Here we go again sigh.
I typed it, you quoted it.

If your theory would hold true a round nose at 800 fps would have the same wounding effect as a SWC or WFN at 1200. This just isn't the case.

 

[Shawn Dodson]

Here we go again sigh.
I typed it, you quoted it.

If your theory would hold true a round nose at 800 fps would have the same wounding effect as a SWC or WFN at 1200. This just isn't the case.

A round nose bullet has an effective diameter about 69% of it's physical diameter. If the bullet is more ellipical (more pointy and streamlined) than round, then the bullet will tend to yaw because the center of gravity is located toward the base of the bullet.

An SWC or Keith-style bullet has an effective diameter that's the same as its meplat. The flat meplat propels soft tissues radially away from the oncoming bullet, which decreases drag because less tissues physically touch the bullet. It will usually penetrate point forward (not yawing) due to a phenomenon called shoulder stabilization. It will penetrate deeper than a roundnose bullet of the same weight and velocity. It will also produce a larger diameter temporary cavity than a roundnose bullet. Depending on a few factors, the temporary cavity can stretch and permanently damage elastic tissues that have been penetrated, but usually does not permanently damage elastic tissues that have been displaced by the temporary cavity but not penetrated.

 

[CDW4ME]

The Strasbourg Goat Tests.
https://content.libsyn.com/p/a/2/b/...nJTcXsea0qvQzHzg__&Key-Pair-Id=K1YS7LZGUP96OI

 

[d2wing]

Bigger and faster is always better. Energy is a reliable measure of how much capacity a round has to do work, damage. But it depends on many other factors to apply that force.

 

[Tinman357]

Topics like this made me do a very deep dive into ballistic studies. I learned a lot, way more than I expected. I soon noticed that heavy bullets at moderate speeds had good street results. At the same time, lighter, faster bullets were arguably just as good.

I came to the conclusion that if slower, big bullets were good and faster smaller bullets were just as good. Then big and fast had to be better. Maybe....

Ultimately, the biggest lesson learned was that a detailed deep study will give you grey hair and an appreciation of alcohol.

I came to the conclusion to carry the largest caliber that I could reasonably conceal, loaded with the heaviest for caliber hollow point bullet and most power that I could reliably control. All that coupled with reliability and accuracy.

Probably the best I can do until better scientific minds than mine can definitively answer that question with provable and repeatable results. This debate has gone on long before I was born and will most likely continue long after I'm gone.

Until then, I make the best choice for me that I can. Everything else is theoretical angels dancing on the head of a pin.


That said, this thread is hugely informative and IMHO one of the better threads here. Lots of good opinions.

 

[mavracer]

A round nose bullet has an effective diameter about 69% of it's physical diameter. If the bullet is more ellipical (more pointy and streamlined) than round, then the bullet will tend to yaw because the center of gravity is located toward the base of the bullet.

An SWC or Keith-style bullet has an effective diameter that's the same as its meplat. The flat meplat propels soft tissues radially away from the oncoming bullet, which decreases drag because less tissues physically touch the bullet. It will usually penetrate point forward (not yawing) due to a phenomenon called shoulder stabilization. It will penetrate deeper than a roundnose bullet of the same weight and velocity. It will also produce a larger diameter temporary cavity than a roundnose bullet. Depending on a few factors, the temporary cavity can stretch and permanently damage elastic tissues that have been penetrated, but usually does not permanently damage elastic tissues that have been displaced by the temporary cavity but not penetrated.

LOL do you ever stop to check your work?
Just for a point of reference when you make up numbers try the math first.
Just a point of reference the meplat of a typical SWC is about 69% of it's diameter.

 

[Shawn Dodson]

LOL do you ever stop to check your work?
Just for a point of reference when you make up numbers try the math first.
Just a point of reference the meplat of a typical SWC is about 69% of it's diameter.

The effective diameter values are from Duncan MacPherson's book "Bullet Penetration".

MacPherson measured a bullet shape factor of .66 for SWC and truncated cone shaped bullets.

If you have a problem with MacPherson's values, then I suggest you take it up with him.

 

[Rodfac]

Stopping power comes from training and practice, not from the numbers stamped on a firearm.

What you hit is more important than what you hit with.

I came to the conclusion to carry the largest caliber that I could reasonably conceal, loaded with the heaviest for caliber hollow point bullet and most power that I could reliably control. All that coupled with reliability and accuracy.

These statements about sum it all up for me....I use the largest caliber, in my carry piece that I can manage, which allows me to speedily fire a 2nd defensive shot with the accuracy needed to stop the aggressor's attack. Smaller guns when firing bigger/faster defensive rounds do not meet my personal carry use criteria. To accomplish the "big caliber/in a shootable gun requirement, I dress around the gun as necessary. YMMv Rod