Which is more important in ballistics?

[Deaf Smith]

In a defensive rd for a handgun which is more important to consider....muzzle velocity or muzzle energy?

Nether.

Shot placement is THE most important thing to consider.

'Energy' and velocity are not the same thing at all and cannot be compared.

Maybe energy and momentum, but not velocity.

Deaf

 

[Bob Wright]

Nanuk wrote:

Just curious, what velocity was that 44 traveling at? I understand the penetration because I have been hunting with 44's for 30 years

.

My load was 25.0 grs. of Dupont (then) IMR-4227 with a 245 gr. cast SWC, Lyman #429421. Out of my 7 1/2" Super Blackhawk it clocked right on at 1400 fps MV. The range was 40~50 yards.

Bob Wright

 

[tipoc]

From Nanuk:

I believe that is why historically the 125 Grain 357 magnum at 1350-1450 FPS and the 115 grain 9mm +P+ at the same velocity seem to defy logic as they perform poorly in gelatine, but work wonderfully on the street.

Everything I've seen shows that they perform well in gelatin (see www.brassfetcher.com). Depending on the round and it's construction they meet law enforcement standards of 12-14" of penetration with expansion. They don't "defy logic" the rounds were built to do what they do and they do it. There is also some hype about how well they performed "on the street" but that's another discussion and they have a record that matches well with other rounds of their class.

tipoc

 

[SRH78]

In a defensive rd for a handgun which is more important to consider....muzzle velocity or muzzle energy?

Of those two factors, energy is more important because energy is the potential to create damage.


As for the rest of the discussion, there are a lot of variables but ultimately it comes down to 2 things. How much energy does a round have and how effectively can it transfer that energy into the target. I shake my head every time someone says bigger and slower is better. If that was true, a 45 would be more effective than a 30-06 and that is obviously not the case. How many here would consider a 5.56 rifle a better weapon than a 45? Probably most of you and rightfully so. How about a 357 magnum vs a 45? Assuming a bullet is placed in the right spot and will transfer it's energy effectively, the round with more energy will do more damage and stop the target more effectively. Now, assuming the energy of two rounds is equal, I would bet on the bigger bullet to transfer it's energy effectively.

 

[MLeake]

SRH78, you assume the round with more energy will also be properly configured to have adequate penetration. This is not always true.

If the round uses a bullet that will penetrate, then yes the higher energy round should have an advantage.

 

[SRH78]

The proper amount of penetration is certainly part of transferring energy effectively.

 

[Glenn Dee]

The will to pull the trigger and put whatever ballistics into play.

 

[jon_in_wv]

I believe any premium JHP ammo available will do the job nicely. After that, practice, practice, and more practice. The more capable you are with your weapon the less you will worry about what type of bullet you use or its velocity. Bullet placement and multiple hits will do worlds more than any difference in velocity, energy, or momentum.

 

[Frank Ettin]

...How much energy does a round have and how effectively can it transfer that energy into the target. I shake my head every time someone says bigger and slower is better. If that was true, a 45 would be more effective than a 30-06 and that is obviously not the case. How many here would consider a 5.56 rifle a better weapon than a 45?...

But that's comparing apples and oranges.

There's no real comparison between a rifle cartridge at 2500 to 3500 fps and handgun cartridges at 800 to 1300 fps. At the range of velocities of most handgun ammunition, and given the elasticity of the target, there's simply not enough energy to make much difference.

For common handgun cartridges, effectiveness for self defense applications will be related to (1) how big a hole the bullet makes; (2) the bullet penetrating deeply enough to hit something important; and (3) the shot being placed well enough to hit something important.

 

[SRH78]

Apples, oranges, pear, grapefruit, or whatever, they still do more damage as a result of the increased energy they are able to transfer effectively to the target.

Besides, you don't have to get to 2500 to 3500 fps to see a difference and some common handguns exceed the 1300 fps you mentioned. Case in point, 357 magnum vs 45 ACP. If the difference in velocity and thus difference in energy didn't matter then the 45 would be a much more potent cartridge. Does anyone honestly believe it is? I can tell you this, a 45 Colt and 454 Casull shoot the same diameter bullet and neither shoots 2500 fps but the difference on game is like night and day. With the Colt, I can shoot cottontails and eat right up to the bullet hole. With the Casull, there isn't much left of a jackrabbit. A 45-70 at 1700-1800 fps with a soft nosed bullet will leave a huge exit wound on a hog. There are plenty of loads for the 357 magnum, 357 Sig, 10mm, and a few others that will do 1500+ fps from a full size handgun. These handguns also aren't shooting a little 22 caliber bullet.

Here is another point. Lets compare 380 and 9mm. Because of it's increased energy, the 9mm's bullets can be made to expand more and still penetrate to a sufficient depth. That is benefit of it's increased energy.

The bottom line is that energy is the potential to do work. In this case the work is damage to the target. As I said earlier, IF you can transfer that energy effectively to the target then the round with more energy will be more effective. That point is not even debatable. What is debatable is which loads in which calibers in which guns actually transfer their energy effectively. I have already said that all else being equal, I would bet on the larger bullet transferring it's energy more effectively but all else is not always equal.

Here is another example that may help make my point a little clearer. A baseball will have more energy than a fillet knife and it will transfer 100% of it to whatever it hits but the filet knife will transfer it's energy much more effectively. Effective, as I am using it doesn't simply mean energy transferred to the target but energy transferred to the target as damage.

 

[Frank Ettin]

...I can tell you this, a 45 Colt and 454 Casull shoot the same diameter bullet and neither shoots 2500 fps but the difference on game is like night and day. With the Colt, I can shoot cottontails and eat right up to the bullet hole. With the Casull, there isn't much left of a jackrabbit...

Again, your comparisons aren't useful. There's a big difference in body mass between a rabbit (cottontail or jack) and a human.

...A 45-70 at 1700-1800 fps with a soft nosed bullet will leave a huge exit wound on a hog...

And that's a matter of the combination of high sectional density of the bullet, a heavy bullet and good bullet construction producing meaningful expansion at the relevant velocities.

But let's see what some people with professional credentials who have scientifically studied the subject say:

• For example Dr. V. J. M. DiMaio (DiMaio, V. J. M., M. D., Gunshot Wounds, Elsevier Science Publishing Company, 1987, pg. 42, as quoted in In Defense of Self and Others..., Patrick, Urey W. and Hall, John C., Carolina Academic Press, 2010, pg. 83):

  In the case of low velocity missles, e. g., pistol bullets, the bullet produces a direct path of destruction with very little lateral extension within the surrounding tissue. Only a small temporary cavity is produced. To cause significant injuries to a structure, a pistol bullet must strike that structure directly. The amount of kinetic energy lost in the tissue by a pistol bullet is insufficient to cause the remote injuries produced by a high-velocity rifle bullet.

  
  
• And further in In Defense of Self and Others... (pp. 83-84, emphasis in original):

  The tissue disruption caused by a handgun bullet is limited to two mechanisms. The first or crush mechanism is the hole that the bullet makes passing through the tissue. The second or stretch mechanism is the temporary wound cavity formed by the tissue being driven outward in a radial direction away from the path of the bullet. Of the two, the crush mechanism is the only handgun wounding mechanism that damages tissue. To cause significant injuries to a structure within the body using a handgun, the bullet must penetrate the structure.

  
  
• And further in In Defense of Self and Others... (pp. 95-96, emphasis in original):

  Kinetic energy does not wound. Temporary cavity does not wound. The much-discussed "shock" of bullet impact is a fable....The critical element in wounding effectiveness is penetration. The bullet must pass through the large blood-bearing organs and be of sufficient diameter to promote rapid bleeding....Given durable and reliable penetration, the only way to increase bullet effectiveness is to increase the severity of the wound by increasing the size of the hole made by the bullet....

  
  
• Urey Patrick was in the FBI for some 24 years, 12 of which were in the firearms training unit where he rose to the position of Assistant Unit Chief. John Hall is an attorney who spent 32 years in the FBI, including serving as a firearms instructor and a SWAT team member.

And in case you or anyone else is interested, I've attached a copy of an FBI paper entitled "Handgun Wounding Factors and Effectiveness."

 

[tipoc]

Folks may want to drop by here and poke around some...

http://www.brassfetcher.com/index_files/9mmvs45ACP.htm

http://www.brassfetcher.com/index_files/357Magnum.htm

tipoc

 

[Hal]

In a defensive rd for a handgun which is more important to consider....muzzle velocity or muzzle energy?

After mulling this over for a few days,,,,,I came to the conclusion that muzzle energy is either there or it isn't - there's not a lot I can do about that figure.

I go with muzzle velocity as being the more important of the two.

When I handload a round, I always have a specific velocity figure in mind that I want to hit.
I don't recall ever starting out to work up a load based on muzzle energy.

OTOH though,,,,the OP specified defensive rd. - not handloads or hunting loads.
There again though,,,I always look at the velocity of a particular round before I look at the muzzle energy.
The second thing I look at is the bullet weight.
I expect a high velocty to translate into a higher energy figure - which is why I say, it's either there or it isn't.

 

[481]

Again, you're comparisons aren't useful. There's a big difference in body mass between a rabbit (cottontail or jack) and a human.

Nice citations, Frank.

It's about the relative magnitude of the cavities - temporary and permanent- as compared to the size of the critter (or bad guy) bein' effected by those temporary and permanent cavities.

 

[peacefulgary]

Energy is more important.

Whether you like a slow and heavy round, or a light and fast round, you still want a high energy round.

Low energy rounds just suck, like a 35g .25 auto from a 2" barrel, which will only give you around 60 ft. lbs. of energy.

Or a 60g .32 auto from a 4" barrel, which only give you around 120 ft. lbs. of energy.




Compare that to a 200g .45+P from a 5" barrel, which will give you over 500 ft. lbs. of energy.

Or a 125g .357 magnum from a 4" barrel, which will give you around 580 ft. lbs. of energy.

Or a 155g .40S&W from a 4" barrel, which will give you around 500 ft. lbs. of energy.

High energy rounds are just more effective than low energy rounds (when it comes to quickly stopping aggressive humans) regardless of the velocity, IF the bullet stays inside the target and dumps all of its energy in to that target.

 

[Bob Wright]

For those who poo-pooed the autopsys of animals, they do represent living tissue, which ballistic gelatin, pine boards, Duxseal and other media do not.

The bullet's relative performance on living animals, large or small, is a good representation of the bullet's effect on human beings. Remember in testing the .45 ACP the Army used live goats for tests.

But a bullet that does not expand on a small critter, won't expand in the human body. And a bullet that expands too soon in an animal, will likely expand too soon on the human torso.

Common sense must dictate any observation.

Bob Wright

 

[Bob Wright]

Hal wrote:

,,the OP specified defensive rd. - not handloads or hunting loads.

Is there any reason defensive rounds can't be both?

Bob Wright

 

[MLeake]

Depends on the animal, Bob.

For large quadrupeds, loads are normally designed with more penetration potential than is considered optimal for human targets. This raises concerns about over-penetration and inadequate expansion.

 

[Bob Wright]

I will say this, from my observations, I elect to use the .44 caliber Remington Semi-Jacketed Hollow Point bullet as my personal defense selection.

I have observed its effect on animate tissue loaded in the .44 Magnum. So, I elect to use it in my .44 Special. Until I'm proved wrong in actual practice, this will be my choice for daily carry.

Bob Wright

 

[Frank Ettin]

...Low energy rounds just suck, like a 35g .25 auto from a 2" barrel, which will only give you around 60 ft. lbs. of energy.

Or a 60g .32 auto from a 4" barrel, which only give you around 120 ft. lbs. of energy....

Actually, the reason these cartridges will tend to perform poorly is not a matter of energy as energy. Rather, these are small caliber bullets making small holes, and with low sectional density and low momentum making for poor penetration.

...High energy rounds are just more effective than low energy rounds (when it comes to quickly stopping aggressive humans) regardless of the velocity, IF the bullet stays inside the target and dumps all of its energy in to that target...

[1] You can't separate energy from velocity because energy is a function of the square of the velocity.

[2] But "energy dump" is meaningless.

[3] See post 51 for the back-up for my opinion.

[4] The effectiveness of a cartridge for self defense is related to the amount of tissue damage and resultant blood loss. And that is related to the diameter of the hole (permanent wound cavity) made by the bullet as long as it penetrates sufficiently.

...The bullet's relative performance on living animals, large or small, is a good representation of the bullet's effect on human beings...

Yes and no. As the animal begins to approach the size of a human, a necropsy (postmortem examination of a non-human subject) will probably provide a fair amount of useful information about the bullet's effect on tissue, but not necessarily its effectiveness for self defense.

The physiological effects of any particular amount of tissue damage would be vastly different for a 200 pound man compared with a 20 pound mammal. The man has greater depth, density and amount of musculature, heavier bones, larger organs and a much greater blood volume. If, for example, a bullet damages 0.5% (by weight) of a 20 pound animal's total tissue mass (about 1.6 ounces), that amount of tissue damage is only 0.05% of the 200 pound man's total tissue mass. And even 2% of the dog's tissue mass is still only 0.2% of the man's.

Understand that there are four ways in which shooting someone stops him:

1. psychological -- "I'm shot, it hurts, I don't want to get shot any more."
2. massive blood loss depriving the muscles and brain of oxygen and thus significantly impairing their ability to function
3. breaking major skeletal support structures
4. damaging the central nervous system.

Depending on someone just giving up because he's been shot is iffy. Probably most fights are stopped that way, but some aren't; and there are no guarantees.

Breaking major skeletal structures can quickly impair mobility. But if the assailant has a gun, he can still shoot. And it will take a reasonably powerful round to reliably penetrate and break a large bone, like the pelvis.

Hits to the central nervous system are sure and quick, but the CNS presents a small and uncertain target. And sometimes significant penetration will be needed to reach it.

The most common and sure physiological way in which shooting someone stops him is blood loss -- depriving the brain and muscles of oxygen and nutrients, thus impairing the ability of the brain and muscles to function. Blood loss is facilitated by (1) large holes causing tissue damage; (2) getting the holes in the right places to damage major blood vessels or blood bearing organs; and (3) adequate penetration to get those holes into the blood vessels and organs which are fairly deep in the body. The problem is that blood loss takes time. People have continued to fight effectively when gravely, even mortally, wounded. So things that can speed up blood loss, more holes, bigger holes, better placed holes, etc., help.

So as a rule of thumb --

• More holes are better than fewer holes.
• Larger holes are better than smaller holes.
• Holes in the right places are better than holes in the wrong places.
• Holes that are deep enough are better than holes that aren't.
• There are no magic bullets.