Penetration Over Maximum Expansion? Handgun rounds

[stonewall50]

So I am just curious why one would value this in a defensive round for humans? Perhaps because I live in Florida? Thick coats aren’t a concern. But that is the only logical thought I can have on the topic. If one were to emphasize penetration, wouldn’t you significantly increase the chances of hitting an unintended target...via over penetration? Additionally, any energy the round was delivering to the body would be lost upon exit. Where as maximum expansion would dump as much energy into the target as possible.

Granted with handgun rounds I’m assuming a balance of course. And that no round is truly going to have “knock down” power unless you are talking magnums. In which case I really don’t think you are talking defensive handguns anymore lol. But that’s another discussion.

So. Can anyone explain the science and thought behind penetration as the point of emphasis (after marksmanship).


Sent from my iPhone using Tapatalk

 

[RickB]

Have you seen the video of four cops firing something like 65 rounds at a fleeing suspect, missing with every round; and you're concerned about overpenetration of rounds that connect?

Seriously, while I understand "every bullet has your name on it", etc., I'd be happy to have two holes leaking rather than one.

I don't think there's enough energy in handgun rounds to really make a difference, so I emphasize marksmanship and penetration (and, preferably, a "pre-expanded" bullet of .45 caliber).

 

[USSR]

Additionally, any energy the round was delivering to the body would be lost upon exit. Where as maximum expansion would dump as much energy into the target as possible.

Uh, it don't work that way. That energy you are referring to is nothing more than a mathematical equation that never killed a soul. What kills is the massive destruction of tissue containing blood vessels which can no longer supply blood to where it's needed, causing a drop in blood pressure, and resulting in a loss of consciousness and/or death. A bullet that creates an exit wound obviously causes more tissue destruction than one that does not, so complete penetration is preferred. There is a reason why the FBI requires a high level of penetration and doesn't simply depend upon expansion.

Don

 

[Wyosmith]

As the former CEO of a bullet company, I can answer this question pretty well.

The thing that is so simple that we often miss it is this:
Bullets don't kill. Bullet HOLES kill.

So the hole need to be through something vital to do a good job of killing or incapacitating a man or beast.

When we look at the small caliber handgun rounds, from 380 Auto and down, to include most 32s, the 25 and the 22s we find that good expansion will inhibit deep penetration.
So, we have a set amount of energy that each round can give us, and we need to try to make the best of that energy. One way is to make a small diameter wound that is deep, and the other is to make a larger diameter wound that is shallower.

The more powerful rounds can give you a good degree of both, but with power comes size and weight and/or recoil.

When I was CEO of Cast Performance I was blessed to have 3 friends in law enforcement that worked in forensics. One for the Feds and 2 for State Agencies. We complied a lot of data from both kills and wounds.

The rule of thumb is that for weaker rounds, you see more deadly and more serious wounds with less expansion (in many cases no expansion) because with expansion the people hit very often had a wound that didn't reach deep enough to kill.
Nothing we can do with bullet design can increase the energy of a given round. We can only use that energy in different ways. "Trick" bullet do NOT make a round more powerful.

So what I teach my students is that a flat nose non-expanding bullets in 25s 32s and 380s is probably the deadliest bullet you can carry in those guns and the standard 40 grain solid in 22 LR is far better for anti-personal use than any HP.

At 9MM Luger you can start to get enough power to make an expanding bullet work and still penetrate deeply. 38 Specials are in the same category, or maybe just a slight bit ahead if you have a longer barrel and a full +P+ load, but the 9MM and the 38 are very close. Going to the 357 magnum and larger is where you start to see more cavitation and full penetration.

The Human element is actually the most important. Marksmanship (or luck) in hitting the enemy in the right place is the most important thing of all. Every deer hunter knows this, but sadly many good guys with hand guns seem to forget at the time of crisis.

But if you can get 9" to 14" of penetration with your bullet and you can shoot it well, you are probably fairly well armed.

If we look only at ballistics the game seems simple. Bigger is better. Faster is better. Bigger AND faster are WAY better. If this were not true than a 32 auto with a 60 grain HP bullet and a 45-70 with a 300 grain HP bullet would be equal.

They are NOT! (what.......no one is surprised????)

Looking at only ballistics is NOT a good idea. The human element is the most important. Marksmanship under stress is the most important factor in winning, in probably 99.5% of the fights. So picking a gun you shoot WELL is vital, and if that gun is less powerful then someone else's gun, don't go up in power just because "his is bigger". Marksmanship is key! If you can shoot a larger more powerful round as well, do it!

If not, stick with what you can shoot well.

 

[K_Mac]

A big hole may look nasty, but unless it is deep enough to incapacitate it is not effective. That is why the FBI set minimum penetration standards in calibrated gelatin. Below the minimum and the odds of failure go way up.

 

[JohnKSa]

That energy you are referring to is nothing more than a mathematical equation...

Kinetic energy is a physical property of moving objects which has been proven to be the measure of the potential of that moving object to perform work/penetrate a target medium.

It can be calculated by a mathematical equation, but it existed before scientists (specifically Willem 's Gravesande) discovered a way to quantify it mathematically in the early 1700s.

 

[44 AMP]

That is why the FBI set minimum penetration standards in calibrated gelatin. Below the minimum and the odds of failure go way up.

And those standards have changed with time. The 9mm JHP that "failed" in the Miami shootout met every FBI standard at the time.

Since then, standards have been changed.

There are two methods through which living creatures are incapacitated by bullets. One is direct tissue destruction of vital organs, the other is loss of blood pressure to the brain. When the pressure drops enough the brain stops working.

SO, put me in the camp that says two holes are better than one for that.

 

[USSR]

Quote:
That energy you are referring to is nothing more than a mathematical equation...

Kinetic energy is a physical property of moving objects which has been proven to be the measure of the potential of that moving object to perform work/penetrate a target medium.

It can be calculated by a mathematical equation, but it existed before scientists (specifically Willem 's Gravesande) discovered a way to quantify it mathematically in the early 1700s.

Here is the mathematical formula for energy:

Energy = Bullet Weight x Velocity^2 / 450,437. In other words, the bullet energy (in foot-pounds) is equal to the bullet weight (in grains) times the square of the bullet velocity (in feet per minute) divided by 450,437.

As I previously stated, animate objects do not die or become incapacitated because of this formula. And the idea that "any energy the round was delivering to the body would be lost upon exit" is ludicrous. It is the destruction of tissue containing blood vessels resulting in a dramatic drop in blood pressure that does the work. And an exit hole promotes the loss of blood and resulting drop in blood pressure. So, IMHO, any shot that does not include both a entry and exit wound is a bullet failure.

Don

 

[CDW4ME]

Get both

45 acp 230 HST or Ranger T hard to beat for penetration and expansion, IMO.
After 4 layer denim, 230 HST penetrated about 13'' / .89 in test I saw on youtube.
In my test of 4 layer denim in front of gallon jugs of water, HST penetrates back of 3rd jug and expands about .87 - consistently.
147 gr. 9mm HST also penetrates back of 3rd jug (after 4 layer denim) and expands .66
Based on gel test and my jug test, expansion and penetration to rear of 3rd jug after 4 layer denim is acceptable performance.

In typical calibers, 230 45 acp HST / Ranger T likely provide most expansion with penetration that meets recommended 12-18''
To support that generalization:
https://www.luckygunner.com/labs/self-defense-ammo-ballistic-tests/
Ranger T 230 - 1'' expansion /14.5'' penetration
HST 230 - .85 expansion / 14'' penetration

What about niche caliber like 10mm or 357 Sig?
First 10mm penetration depends on bullet, anybody that blanket generalizes 10mm as over penetrative is misinformed.
In my 4 layer denim jug test, 357 Sig 125 Gold Dot expands and penetrates into 4th jug
10mm 155 XTP handload @ 1,400 fps penetrates into 4th jug and expands about .65
There is a visible difference in impact and damage to 1st jug with 10mm (over 600# KE) versus 45 acp or 9mm (about 400# KE)

A commonly seen generalization is that handgun bullets only damage tissue they physically touch, no damage from "temporary" cavity; this may be true for "common" calibers, IDK; but, from what I've seen that generalization doesn't apply to KE over 600# in this example, 10mm:
https://thefiringline.com/forums/showthread.php?t=591069

Seeing 10mm result in tissue , makes me wonder if 10mm might be "better" than 45 acp for SD (same shot placement) - offers an extra round capacity in 1911.

What about recoil? Subjectively recoil is not much different than a stout 45 acp when shot from full size 1911. Recoil calculations support my impression:
10mm Handload 180 Nosler @ 1,228 fps / 603# KE - recoil energy 9.2 - PF 221
10mm Handload Nosler 150 JHP @ 1,402 fps / 655# KE - recoil energy 9.4 - PF 210
45 acp Remington Golden Saber 185 +P @ 1,157 fps / 550# KE - recoil energy 9.0 - PF 214

The Noslers typically fragment and blow jacket at those speeds, but jacket in 3rd jug with lead core, lead core hits back of 3rd jug and expands about .69

My 10mm handloads suit me, but are not maxed out, Underwood offers the same bullets driven a bit faster:
150 Nosler @ 1,500
https://underwoodammo.com/product/handgun-ammo/10mm-auto-150-grain-jacketed-hollow-point/
180 Nosler @ 1,250
https://underwoodammo.com/product/handgun-ammo/delta-elite-10mm-auto-180-grain-jacketed-hollow-point/

 

[stinkeypete]

Wyosmith’s post is experience and science of a complex question.
By the way, l still have two nearly full boxes of Cast Performance hard cast in .357 if anyone has been looking. Awesome product, but I left that caliber.

As for simple equations, they work for simple questions such as “which bullet can push a box filled with clay the farthest, assuming the bullet is captured by the clay.”

If the bullet penetrates, we must subtract the exit energy.

If we want to know how much damage is done to a living thing, much more has to be accounted for in a complex model combing many perturbations to the simple case theory. Science and Math are awesome, but must give way to experimental data. The model is fit to the data and improved again and again.

In the end, the experiment wins when the overwhelming variable is “where did you hit the subject?” That boils down to skill under extreme stress.

Me? I shoot deer and stay away from trouble.

 

[T. O'Heir]

Thick coats aren’t a concern anywhere. Down nor Melton cloth are bullet proof.
"...unless you are talking magnums..." Neither do they. Physics doesn't allow it. If a bullet can knock anybody down, its recoil will knock the shooter down too.
"...four cops firing something like..." That's the typical lack of training, mandatory practice and skill.
"...FBI set minimum penetration standards..." The FBI is not who sets standards for anything. And a minimum penetration standard means squat if you don't hit what you shoot at.
Of the eight agents at the scene of the Miami Shootout, 5 of 'em had .38 revolvers. Both criminals were military trained and had rifles. Any handgun loses in a gun fight against riflemen. Easier for FBI management to blame the tool than admit to poor training.

 

[jmr40]

I think Wyosmiths post does the best job of describing this. Not a lot more to add.

I don't think energy numbers are useless, but they are often misunderstood. As long as you are comparing similar projectiles the one with more energy will probably cause more damage. But when you start comparing projectiles with very different construction the numbers can be misleading.

I'm in the camp that believes penetration and placement are most important. Expansion and/or larger diameter holes are nice, but are secondary.

 

[USSR]

"...FBI set minimum penetration standards..." The FBI is not who sets standards for anything.

Wrong again as usual T. O'Heir. The FBI set standards for the ammunition that is to be issued to their agents.

Any handgun loses in a gun fight against riflemen.

Tell that to the 2 Capitol police officers who killed the rifle wielding gunman who seriously wounded Congressman Scalise in Alexandria, Virginia last year.

Don

 

[Bill DeShivs]

I see a lot of "2 holes is better than one."
It doesn't really matter if a bullet exits. It's what it hits while inside the body that counts.
Blood loss outside the body is really irrelevant.

 

[K_Mac]

I see a lot of "2 holes is better than one."
It doesn't really matter if a bullet exits. It's what it hits while inside the body that counts.

I agree. Surviving a gun fight depends on incapacitation of the attacker. Incapacitation due to blood loss caused by an exit hole is not likely to be the deciding factor.

 

[Cheapshooter]

So, IMHO, any shot that does not include both a entry and exit wound is a bullet failure.

What? Do you think the human body is a big hollow tank filled with blood, and two holes in it's exterior would drain it quicker?
That exit hole you so strongly desire is quite possibly the beginning of an entrance wound in a target you never intended to shoot. Or do you even care?

 

[USSR]

Quote:
So, IMHO, any shot that does not include both a entry and exit wound is a bullet failure.

What? Do you think the human body is a big hollow tank filled with blood, and two holes in it's exterior would drain it quicker?
That exit hole you so strongly desire is quite possibly the beginning of an entrance wound in a target you never intended to shoot. Or do you even care?

Yes, two holes causes more loss of blood because logically it has penetrated further than the bullet that stopped somewhere in the body. Logic is funny like that. Also, you seem to forget that a miss could also put a "wound in a target you never intended to shoot". Did you hear about the police who shot at a suspect 99 times and only hit him 20 times? This was just about a month ago. Don't they even care? I went to an active shooter seminar put on by our local Sheriff's department, and even the Sheriff admitted that law enforcement officers weren't the best shots. So, the point is, IMHO (you do know what IMHO means?) you want maximum penetration.

Don

 

[Danoobie]

Let's take a step back to empirical data for a moment. When Gavrilo Princip
shot the Archduke Ferdinand and his wife, he killed them both with 1 round of
rather humble 32ACP caliber, each. The point being sometimes you do everything
wrong, and get the desired result. By extension, other times you do everything right, and
nothing effective or tangible comes of it.

But let's digress for a moment, shall we? What if you were to learn
(rhetorical Q, AFAIK, no such thing exists) that there were a 9mm ammo with the exact wounding characteristics of 45ACP? Would you switch to this ammo, or keep shooting the 9mm ammo you currently use?

 

[JohnKSa]

Here is the mathematical formula for energy:

Energy = Bullet Weight x Velocity^2 / 450,437. In other words, the bullet energy (in foot-pounds) is equal to the bullet weight (in grains) times the square of the bullet velocity (in feet per minute) divided by 450,437.

That is a reasonably accurate statement of the formula, although it would be more correct to state that it is the formula for kinetic energy as there is more than one kind of energy and other types of energy are not represented by the formula for kinetic energy. In addition, the velocity is in feet per second, not feet per minute.

Finally, the constant which is stated as ‘450,437’ is actually not a whole number, nor is it an arbitrary constant. It is a combination of converting grains to pounds (divide by 7,000) and then pounds to slugs (divide by 32.174049...). Slugs are a unit of mass and it's necessary to convert to mass since the formula isn’t actually based on weight, it is based on mass. The final factor in the constant is ‘2’ from the ½ in the actual formula for kinetic energy which is ½ (mass x velocity squared).

As I previously stated, animate objects do not die or become incapacitated because of this formula

It is true that “formulas” and “equations” themselves don’t have any effect on the real world.

However, equations and formulas often accurately represent things in the real world. In this case, the equation/formula quantifies kinetic energy, a real-world, physical quantity. For nearly 300 years, the scientific/technical community has accepted the equation as a correct quantification of kinetic energy and have not only experimentally verified the equation, but also relied upon it to produce accurate results in the real world.

Kinetic energy is not just the product of an equation or a mathematical construct, it really does exist in the real world. It really does affect the real world. It really does provide a measure of the potential of a moving object to do work. Understanding it really does allow a person to predict certain aspects of how a real-world moving object will interact with other real-world objects. It’s certainly not the entire story, when it comes to terminal ballistics, but it is definitely part of the story and understanding it properly will provide insight that is obscured if one tries to ignore it.

I don't think energy numbers are useless, but they are often misunderstood.

Well said.

 

[Cheapshooter]

Yes, two holes causes more loss of blood because logically it has penetrated further than the bullet that stopped somewhere in the body. Logic is funny like that. Also, you seem to forget that a miss could also put a "wound in a target you never intended to shoot"

Maximum expansion and penetration deep enough to damage vital organs without over penetration will also cause a large amount of blood loss.

Yes, missed shots could result in hitting unintended
Targets. But isn't it the responsibility of the shooter to minimize the possibility. Especially buy not intentionally using ammo that will over penetrate.