Stopping Power - Knock Down Power

Status
Not open for further replies.
I don't know much about stopping power,
but knock down power I have had a lit'l do do with,
while competing in IHMSA.

A 44 Remington Magnum cartridge loaded with a 220 gr jacketed bullet
over 22.0 grains of 2400 out of a 8 3/8" S&W model 29-2 will 'ring'
a hard set 50 pound ram at two hundred meters.

A 44 Remington Magnum loaded with a 220 jacketed bullet
loaded over 23.5 gr. of 2400 in a S&W 29-2 / 8 3/8" barrel will
knock down a hard set fifty pound steel ram at 200 meters...

.
 
Last edited:
Thanks to all of you who took the trouble to prepare lessons in ballistics, physics and math. But I'm old and simple-minded--a simple man, anyway.

I just read all the way through this again. Now my brain hurts, and I haven't the slightest inclination to change my choices of a carry gun and ammunition with which to load it. The combination is what I selected because it has proven to stop threats countless times for many years, though it won't knock anybody down.

Shooting it to stop a threat effectively is up to me, and I hope I ever have to.

So far so good.
 
Last edited:
Whether you chose “knockdown power”, “stopping power”, “dropping factor”, it all boils down to what is the most effective cartridge for self defense. For revolver, it is the .357 magnum 125 grain hollowpoint. For handguns, it is the .45 ACP 230 grain FMJ. For shottys, the 1 oz slug OR the 9 pellet 00.

It makes sense to me: use what has shown on the streets and in war if you want the most stopping power, no matter if you like the term, or otherwise.

Sanow and Marshall. When I first read them, I thought they'd discovered something remarkable. Then I rethought it. The very cartridges they found to be the best one shot stoppers are the ones used by professionals like police and other serious shooters. What they thought was due to bullet design was a statistical proxy for skill and training, reflected in, you guessed it, shot placement.
 
Sanow and Marshall. When I first read them, I thought they'd discovered something remarkable. Then I rethought it. The very cartridges they found to be the best one shot stoppers are the ones used by professionals like police and other serious shooters. What they thought was due to bullet design was a statistical proxy for skill and training, reflected in, you guessed it, shot placement.

Marshall and Sanow, what a joke.
 
Thanks to all of you who took the trouble to prepare lessons in ballistics, physics and math. But I'm old and simple-minded--a simple man, anyway.

I just read all the way through this again. Now my brain hurts, and I haven't the slightest inclination to change my choices of a carry gun and ammunition with which to load it. The combination has stopped threats countless times for many years, though it won't knock anybody down.

Shooting it to stop a threat effectively is up to me.

Grab some popcorn, and iced tea, get comfy in your easy chair and laugh at the hyperbole and your head will feel better.
 
It gets so garbled becouse too many are here just to argue and make no point at all.
It's simple, forget about human targets. Line up a dozen empty scuba tanks and shoot them from 7 yards with .22, .380, 9m, .45, 357, .44 mag, .50.
You will see that some will knock down the tank and some will not. That is real and measurable performance of knock down power.
Do the same using ballistic gelatin, that is real measurable performance for potential stopping power.
It doesn't matter if it will always stop a man, but it is still measurable and real.
Two ton jack wont lift 10 tons, but doesn't mean it doesn't have two tons lifting power.
 
Don’t mean to be calling it a bromide, but

I have never been put in a position to be attacked by a bowling pin.
This is a self defense sub forum, right....? :rolleyes:
 
Last edited:
After reading all of this......

I guess, I'll jest go though with my

idee of up-grading my EDC to a 45 Super....

Carry alot and shoot a lit'l. Oh, I'll jest use +P for practice. ;) :D :rolleyes:


.
 
Last edited:
You may not like the answer, but I'm not all that crazy about the question. What do you call WHAT? The OP asks what you call "it," after naming two different concepts, one often misunderstood, the other non-existing in self-defense scenarios not involving a rabid mouse. The problem isn't what you call those two different concepts, rather what mistaken notions you have about them.

Many of the answers, probably including the one you didn't like, attempt to answer the deficiencies exposed by the original question. Many answers were useless or misleading because the poster didn't know the difference between KE and momentum, and had little idea of whether either applied to what may have been under discussion.

I am not sure why you are arguing with me. I thought a half page of math was a funny response to the original question. It was humorous to me. There was no like or dislike. I don't really care much about the terminology or KE, momentum or bowling pins. I think knockdown power is poor terminology and math is not useful in evaluating handgun effectiveness unless perhaps we are talking about hunting, but will not lose any sleep over it or feel slighted if you like the term or feel otherwise.

Maybe we should just invent our own term. How about DE (dissuasion effectiveness). Or, to incorporate math for those so inclined, COD (coefficient of dissuasion).

(dissuade v. - persuade (someone) not to take a particular course of action)
 
Guys, who cares about formulas?

The number of North American big game animals taken with cartridges like the .44-40 and even .32-20 is quite large. Headshots to whitetails and the like with .22LR, albeit at pretty close range. Last time I checked, the largest moose in Idaho history was taken with a .30-30.

While not the top choice, 7mm Mausers have taken bull elephant with a single shot.

Natives to the Arctic successfully hunt polar bear with .223s and .243s all the time.

What's the common theme here? BULLET PLACEMENT.
Your examples are scewed because of the headshot. Remove that, small calibers in hunting large game or defending yourself against attackers are woefully inadequate with body shots. Everyone thinks they can make a headshot until the target is moving.
 
Last edited:
In looking up "why was the 1911 pistol invented" the term stopping-and stopping power was used to describe the need that the 45 caliber hand gun filled.

Back in the days before expanding bullets, bullet dia & mass were required to produce those lovely big holes. Todays jhp in handguns & soft points in rifles allow smaller bullets to make those same big holes. Still, knock down or energy dump or stopping power, doesnt really come into play with pistols. You get close when you get into the 44mag & hvy 45 colt in longer bbls, but still not a low end rifle load.
 
Last edited:
...
I thought a half page of math was a funny response to the original question. It was humorous to me.
...

I’m the guy that did the math and you’re being disingenuous. My response to the original question was simple. That knock down power and stopping power exist as concepts, but not in pistol cartridges. Period. Go back and look it up.

The math came about when a poster posted nonsense about recoil and “knockdown power” being related to KE and that poster made the comparison to knocking down bowling pins with a .45 acp and a .22. I challenged him on that, he said he didn’t believe it and to “show him the calcs,” so I did.

The math was at the level you’d see in a high school science class and was directed to the poster that specifically requested to see the math. If the math was uninteresting or too hard for you, all you had to do was skip the post.
 
Last edited:
It gets so garbled becouse too many are here just to argue and make no point at all.
It's simple, forget about human targets. Line up a dozen empty scuba tanks and shoot them from 7 yards with .22, .380, 9m, .45, 357, .44 mag, .50.
You will see that some will knock down the tank and some will not. That is real and measurable performance of knock down power.
Do the same using ballistic gelatin, that is real measurable performance for potential stopping power.
It doesn't matter if it will always stop a man, but it is still measurable and real.
Two ton jack wont lift 10 tons, but doesn't mean it doesn't have two tons lifting power.

Not really. it is a measure of bullet momentum & dwell time on the target. All the service rounds have about the same ME, +/- 50ft#. Depending on the bullet though, momentum, is vastly diff. So no, doesn't tell you anything really about a bullets ability to stop a man.
Its about the bullet & what it does to the target. A 9mm jhp w/ slightly less ME than a 45 solid, I am taking the 9mm jhp all day because it will crush more tissue & do more damage to the target. Yet the 45 will knock still over with more authority, which again means little.
 
...
Since people claim that stopping power does not exist with a handgun, what term would you use? ...

How about just referring to "Effectiveness"?

Then, of course, you're back to trying to defining "effectiveness", which is likely going to remain a matter of perspective and being situationally dependent. ;)

For the rest of the thread ...

Folks, it's a handgun. It's not a shotgun or a rifle. (And not even all shotgun or rifle GSW's are "guaranteed" to be immediately effective at stopping someone from continuing whatever volitional actions it was that caused someone else to shoot them in the first place.

Carry what you got, or what you like, or whatever you happened to have brought along on whatever particular day/night something bad comes calling.

You're the tool (weapon) user who has to make it work when it's desperately needed. Don't blame the tool you chose if you can't make it work for the circumstances you failed to anticipate.

It's a handgun. A handgun.
 
Status
Not open for further replies.
Back
Top