Handgun Stopping Power Revisited

[44MAG#1]

Sometime back I followed a thread written by an assistant to the Georgian forensic pathologist. They did like 5 autopsies a day. Not all were gun shot victims. He worked there like 15 years.
His opinion was - It is not what you start with,it is where the bullet ends up. His opinion was that too many variables to determine "best stopping power". Where one bullet would be ideal it may not be ideal if it had to penetrate bone. The distance to vital organs may differ depending on the position of the victim to the shooter.
His choice of defensive firearm was a .40 S&W with hp bullets.

That is the reason when I sometimes carry a 40 S&W Glock M27 it is loaded with a 200 grain XTP Hornady or a 200 grain hard cast FP at 900 to 930 FPS from that firearm.

[cainttype]

The desired effect in all of these comparisons is to end a dangerous encounter requiring deadly force immediately. If “immediately” isn’t accomplished “As quickly as possible” is a secondary goal.

In agreeing with the FBI assessment, a little clarification might be in order.
Penetration is of utmost importance because… 1)Reaching the vitals is critical, but reaching the SPINE results in instantaneous incapacitation….Two holes bleed out faster than one…Knowing that heavy clothing and/or heavy bone (arms, for instance) will reduce penetration is something that needs to be considered. The FBI trials after “The Shootout in Miami” fiasco kept that front and center during their research.
2)Permanent wound channel… Two holes bleed out faster than one (see above)… Larger diameter bleeds out faster than small… Sometimes lost in the discussion, a smaller bullet that “almost” clips the spine could be a larger diameter that DID clip the spine (see (1) above).
None of the above means anything if you miss.

My conclusion/opinion… The largest diameter PERMANENT wound channel that reliably penetrates from any angle through the vitals AND spinal area is a VERY good choice, if you can deliver the bullet where you need it.

“Stopping Power” and how to define it?…. In the hunting field or in self-defense those criteria cover it pretty well for me.

[Burnt Fingers]

Sometime back I followed a thread written by an assistant to the Georgian forensic pathologist. They did like 5 autopsies a day. Not all were gun shot victims. He worked there like 15 years.
His opinion was - It is not what you start with,it is where the bullet ends up. His opinion was that too many variables to determine "best stopping power". Where one bullet would be ideal it may not be ideal if it had to penetrate bone. The distance to vital organs may differ depending on the position of the victim to the shooter.
His choice of defensive firearm was a .40 S&W with hp bullets.

The problem there is that they only see the ones that die. Take Chicago as an example. On a weekend they might have 50 people shot but only 6-7 deaths.

One has to account for the people that didn't die too. That runs into a problem. The surgeon is going to patch them up and really not pay attention to much else. Some of the dindonuffins don't even need surgery.

[Murphy]

1 shot stopping power in a handgun is an endless debate and will remain so until the end of time. And that's all I have to say about that.

Murphy

[Buck Shot]

1 shot stopping power in a handgun is an endless debate and will remain so until the end of time. And that's all I have to say about that.

Murphy

+1

All I know is that the stopping power of any handgun is generally gonna be a small fraction of that of any long gun!

[Michael J. Spangler]

I wrote a ton here but too many distractions with the kids so it’s all jumbled.

Shot placement is king as long as we use a cartridge that meets the known penetration standards.
Get rid of the variable of humans and treat them as animals. If someone had the ability to be a drugged up adrenaline filled animal then we have to act as if they will be this way every time.
So only a CNS hit will be a one shot stopper.

Lucky Gunner shows plenty of modern ammo that meets this criteria given proper shot placement.
I don’t think modern 357 will do any better than modern 38 special.

With the proper placement they will both penetrate to result in a CNS hit.

Expanding bullets or larger diameter bullets that cut wider holes and drain the blood faster are all icing on the cake.

[44MAG#1]

Is anything NEW being said? I just wish something NEW could be introduced in the "STOPPING POWER" topics.
It sure would make good reading though.

[Michael J. Spangler]

Is anything NEW being said? I just wish something NEW could be introduced in the "STOPPING POWER" topics.
It sure would make good reading though.

Maybe that’s the point? Nothing is new. The body is still the same. The bullets are more or less the same, possibly more effective. I don’t think we will see anything new until one or the other changes.
Or until some under informed part time writer and keyboard warrior comes up with some new bogus theory.

[charlie b]

Nothing is new except some of the bullet construction. At least now days I can find bullets that will penetrate and expand in "difficult" circumstances. A lot different than back in the 80's.

[BunkTheory]

150 grain jsp out of a .308 winchester can make a human head explode. Lot more powerful then a handgun.

Yet at short range a 158 jhp out of a 357 magnum comes awful close.. 44 magnum does the job rather effectively and requires a lot of money on repainting the walls, cieling, and new carpets and lots of new furniture.

Stopping power is NOT something you get from the bullet, its not a magical talisman. On paper a percussion revolver in .44 has the same rough ballistics as a 38 special.. yet its just as effective as a 44 magnum if i grab your throat, smile, and put the muzzle in your ear before i fire.

[AZ Pete]

nothing new, but magazine capacity. Reflecting on "stopping power" and my previous comment re: bullet placement, I have been unfavorably impressed by the gross number of rounds expended in many police shooting news reports. It often appears that not even the majority of rounds hit the target, much less a vital area. Maybe that is only my impression....

[Tar Heel]

It's a academic and pointless exercise for the nerds. Depends where the bullet is placed. Shoot any mammal in the brain with a 22LR and it's a 100% "one-shot-stop" with a 22LR or a 32 or a 9 or a 40 or a 45...........

There are simply too many variables to work into the formula. When you think you have a formula, see the first sentence.

[Tar Heel]

To follow up on my previous post I offer the following "old guy" perspective on this endless exercise.

I think that we can all agree on a few things:

• A fair amount of horsepower is not a bad thing.
• Multiple shots in rapid succession are better than a single shot.
• Center mass shot placement is far better than an alternative location.
• Delivery of all the above is not possible by most people.
• And finally: know that luck will always rear its head.

It is also important to recognize that you are probably NOT the warrior you believe yourself to be nor do you possess the requisite lethal force training to survive an actual gunfight. It is best to AVOID a gunfight and don’t worry about the best caliber to use in a deadly confrontation. Use what you have and use it well if need be.

Instead of wondering and worrying about academic theory, why not spend the time on the range with the grandkids, a bunch of empty Coke cans, and a bucket of 22LR ammo.

[BunkTheory]

To follow up on my previous post I offer the following "old guy" perspective on this endless exercise.

I think that we can all agree on a few things:

• A fair amount of horsepower is not a bad thing.
• Multiple shots in rapid succession are better than a single shot.
• Center mass shot placement is far better than an alternative location.
• Delivery of all the above is not possible by most people.
• And finally: know that luck will always rear its head.

It is also important to recognize that you are probably NOT the warrior you believe yourself to be nor do you possess the requisite lethal force training to survive an actual gunfight. It is best to AVOID a gunfight and don’t worry about the best caliber to use in a deadly confrontation. Use what you have and use it well if need be.

Instead of wondering and worrying about academic theory, why not spend the time on the range with the grandkids, a bunch of empty Coke cans, and a bucket of 22LR ammo.

There was a book about old west gunfighters that was wrote in the late 1880s. I believe it was as qoute from hickock that settled the issue

"its best to use a rifle, and shoot them from 100 yards, and from behind"

[pettypace]

Here's a chart of "Wound Trauma Incapacitation" numbers similar to Table 11-6 in Duncan MacPherson's book Bullet Penetration: Modeling the Dynamics and Incapacitation Resulting from Wound Trauma. I've added columns for .25, .32, and .44 caliber (using MacPherson's math) and deleted his rows for JHPs with 12" and 10" penetration (where MacPherson introduced an arbitrary "penetration factor" penalty to discourage use of under-penetrating JHPs).



The chart (and MacPherson's WTI Model behind it) is more sophisticated than it appears. MacPherson's behind the scenes calculations include bullet weight, velocity, diameter, and nose shape. For the non-expanding bullets, the numbers assume at least 18" penetration in bare 10% ordnance gelatin. And the WTI numbers ignore the last 3" of any penetration (where lower bullet velocity minimizes tissue damage) as well any penetration past 15" (beyond which the bullet is assumed to have exited the target). MacPherson's WTI model is limited to normal handgun velocities (say, 400-1600 ft/s) and does not deal with "tumbling" bullets. The chart is not intended for big game hunting where penetration beyond 15" would not be ignored.

For perspective, the infamous .38 Long Colt (as well as .380 and 9mm FMJ) produces 16 grams of WTI wound mass (.38 cal. All Others) and was judged inadequate. At the other end of the scale, the 12 gauge rifled slug (437 grains at 1500 ft/s mushrooming to 1.1 inch diameter and penetrating to 14 inches from Fackler's wound profile) gives a WTI wound mass of 155 grams.

Because MacPherson's WTI model takes bullet nose shape into account, some interesting comparisons are possible. For example, a well-designed JHP from a .32 ACP (25 grams), a target wadcutter from a .38 snubby (24 grams), and .45 ACP hardball (26 grams) all produce approximately the same WTI wound mass.

Of course, MacPherson's WTI model does not discount the importance of training, accuracy, shot placement, magazine capacity, recoil, concealability, and (dare I say it?) good luck. Instead, it suggests that when shot placement is less than ideal, the mass of non-vital tissue destroyed by contact with the penetrating bullet might be decisive. I think that comes as close to the idea of "stopping power" as we're likely to get.

[44MAG#1]

Is this the reveal I have been waiting on? Kinda disappointing.

[pettypace]

Is this the reveal I have been waiting on? Kinda disappointing.

Who's to say what you've been waiting for?

Are you disappointed to learn that your 40 S&W 200 grain FP cast that "trundles along slightly over 900fps" might not be any more effective than a good load from a .32 ACP or a .38 snubby with target wadcutters?

If you disagree with the model, fine. But please explain your reasoning. Your disappointment doesn't count for much.

[44MAG#1]

Not worth it.

[charlie b]

Where do they relate the WTI numbers to how fast (or slow) someone is actually incapacitated, ie, is unable to aim and pull a trigger?

From what I can tell it just indicates how fast someone will bleed out. That means quite a few seconds for them to still be in the fight.

Sent from my SM-P580 using Tapatalk

[pettypace]

Where do they relate the WTI numbers to how fast (or slow) someone is actually incapacitated, ie, is unable to aim and pull a trigger?

From what I can tell it just indicates how fast someone will bleed out. That means quite a few seconds for them to still be in the fight.

Good question! Too bad MacPherson isn't here to give a good answer. But I'll try...

There's talk of different modes of incapacitation: Psychological incapacitation is when the attacker is unwilling to continue. Physiological incapacitation when the attacker is unable to continue.

Physiological incapacitation might be the instantaneous result of damage to a part of the central nervous system or the slower result of blood loss from damage to a major organ or blood vessel eventually depriving the brain of oxygen and stopping the attack. In either case, adequate penetration and fortuitous shot placement are more important than horsepower. So, a .25 ACP that hits a vital structure might work where a .45 ACP that just misses a vital structure might not.

But MacPherson is talking about something else. He writes that the "WTI scale is a rating of the effectiveness of cartridges when... bullet impact location is not ideal." So, the question is whether physiological incapacitation can be achieved through damage to non-vital tissue.

This may sound far-fetched. But MacPherson harkens back to the 1904 Thompson-LaGarde Chicago Union Stock Yard tests where beef critters were slaughtered with a variety of handgun cartridges to determine the most effective cartridge for the US military. The testing included cartridges from .30 Luger to .476 Webley and eventually resulted in the adoption of the .45 ACP and Colt's 1911.

One phase of the Thompson-LaGarde testing involved rapid fire shooting into "non-vital parts" of the beef critters until the animals finally dropped. The results went something like this: the animals were brought to their knees after three to five shots from the heavy .45's, after seven shots from the .38's, and failed to succumb after ten shots with the .30 Luger.

So, MacPherson used his penetration modeling to determine total "wound trauma incapacitation" numbers for these tests and found that, regardless of the caliber, it took about 220 grams of wound mass to non-vital parts to incapacitate a steer. With the smaller calibers it just took more shots to finally reach 220 grams of wound mass.

MacPherson speculates that when shot placement is less than ideal, an attacker might actually be physiologically incapacitated when enough non-vital tissue is destroyed by the bullet (or more likely, bullets).

If I remember right, MacPherson pegs this "critical mass" (my term, not his) at around 30 to 40 grams and somewhere suggests that if that's not enough, then you probably need more.

MacPherson isn't dogmatic about any of this. He simply says that adequate penetration is critical -- don't leave home without it. Fortuitous shot placement might be decisive -- but you can't count on it. And when shot placement is less than ideal, the accumulation of as much wound mass as possible is your next best bet. Beyond that, he provides what he believes to be the best way to calculate the wound mass numbers. The chart below shows a range of those calculations:



Obviously, there are lots of ways to accumulate that critical mass of 30 to 40 grams (or more) of wound mass. And if you're lucky, you might not even need it. After all, a single CNS hit from your vest pocket .25 will cause instant incapacitation.