Handgun Stopping Power - Efficacy?

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Boberama

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I was going to do a .40 vs .45 thread as my first post but I guess that would be flogging a dead horse, so I decided to do this instead.
I thought of the idea of "efficacy" myself after messing around with different formulas but recently I found that one L. Niel Smith had thought of the same thing. I think it is a pretty good measure of a cartridge's " stopping power", but I am unsure about rifles after I found a .50 AE rated higher than a .30-06. (314 vs 216)

Efficacy = frontal area x ft-lbs energy

.45 ACP
230gr FMJ 830 fps 352 ft-lbs = 56
200gr FMJ 975 fps 422 ft-lbs = 68
185gr FMJ 1050fps 453 ft-lbs = 73

.40 S&W
165gr FMJ 1150fps 485 ft-lbs = 61

9mm Luger
124gr FMJ 1120fps 345 ft-lbs = 34
124gr FMJ 1250fps 430 ft-lbs = 43

.44 Special
246gr LRN 785fps 337 ft-lbs = 49

Seems like a pretty good indicator to me.
What do you think?
 
Just my opinion...

Any "formula" that uses ft. lbs. of energy is useless from a ballistics standpoint.

For handguns...I still say pure old fashioned momentum is the best unit of measure.
 
I don't know about that...
Momentum would come into play if the bullet struck a bone mass.
But a ten pound bowling ball moving at 1fps has more momentum than a 40 grain CCI Stinger going at 1600fps.

You stick to your formula and I'll stick to mine.

But momentum certainly does come into play when striking a bone mass, that's why a .45 ACP will move a bowling pin much farther than a 9mm.
In soft flesh I think "efficacy" is better than momentum. The figures just sound about right to me.

And the heavier calibres such as .45 ACP and .50 GI outstrip higher energy calibers such as 9mm and .357 SIG, since area comes into play.
 
I think it ignores the recent research into developing effective hollow points, which create a larger frontal area after impact.

I'm a fan of "big works", so this isn't a personal point I'm trying to prove...

But, a smaller diameter projectile at higher velocity, that permits expansion, can provide similar stopping power to a larger diameter projectile.

The problem is, hollow points don't always work. ;)
 
Please compare apples to apples... defense calibers... not extreme ends of the spectrum like a bb and a bowling ball geez. I've gotta learn this stuff ya know!
 
Momentum:

180 grain 30-06 (for comparison) : 69
230 grain 45 acp: 27
55 grain 223 Rem: 23
124 grain 9mm: 19
BB at normal velocity : 4
BB at 16,800 fps : 69 (equal to a 30-06...that might actually kill an elk after all, I didn't realize it would be that fast)
 
but for the sake of argument extreme examples make it easier to compare.
Click to expand...
Not really. It may seem that way, but it really just clouds the issue.

Obviously a 70,000 grain bowling ball moving 1fps is not analogous to a typical self-defense handgun bullet, nor is a 5 or 6 grain BB moving at 15,000 fps (to equal 500S&W energy).

The problem with comparing the practical differences in performance between typical handgun self-defense calibers is that they're so similar in performance. Trying to draw conclusions from extreme examples is fruitless.

This question has been hashed & rehashed for the last century or so with no definitive answer. Just a tiny bit of thought will make it plain that the reason the debate rages on is NOT because there's a lot of difference in performance. If there were, it would be very simple to pick a winner...
 
I'm just saying that all the efficacy numbers for handguns that I have calculated seem about right. Personally, I do factor in momentum, but as penetration, not stopping power.

Here's my penetration formula for FMJ's.
(Grains x Velocity) / (Caliber x 100)^2

I think it might be more realistic to have area instead of caliber, but whatever.
I put the two number together, like this:

.45 ACP 230gr FMJ 830 fps = 56 / 93

.357 SIG 125gr FMJ 1350 fps = 50 / 134

9mm Luger 124gr FMJ 1120 fps = 34 / 110

You keep penetration and stopping power seperate because this is not killing power, it's stopping power. Don't try this formula with Glasers, etc.

( And the slash is to seperate the two numbers, not divide them.)
 
Ok... someone go clean out Costco for all their Kirkland Signature weiners.

Build a relatively elastic box possibly out of lexan (because a wooden crate will crack from the pressure of the impact) and stand a bunch of weiners vertically and densely for about two feet deep and wide enough for the round to stay encased in the box.

Shoot it with a .40. Count all the damaged weiners.

Shoot it with a .45. Count all the damaged weiners.

Wam. Bam. Thank you Ma'am!
 
I've performed that test...on live deer. (they were not alive for long afterwards)

Both calibers did the job in fine fashion...the 45 did it slightly better with pretty much the same shot placement and range. I could not see any noticeable advantage to the 10mm either...the wounds looked the same. I do agree though...the 10mm offers more extended range.

The 9mm didn't fare so well...my son finished that one with a quick follow up shot from the 308.
 
And don't get me wrong, I own two Colt 1911's in .45ACP, and one in .455 Webley (that's right, it has stippling on the front strap and slide top. Weird.).
I'm also a fan of the big bullet camp.
But momentum doesn't hold up as well as energy, and gun rags publish energy instead of momentum. If momentum was the deciding factor it would be published. But it's not.
But energy alone isn't either. It's efficacy.

.303 works very well on deer from close to medium range, from my No.5 Mk.1. Handgun hunting is prohibited here...what can you expect when the only provincial parties are the Liberals, the New Democrats ( even worse ), and the Greens? ( Literally Communists! )
 
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.303 works very well on deer from close to medium range, from my No.5 Mk.1. Handgun hunting is prohibited here...what can you expect when the only provincial parties are the Liberals, the New Democrats ( even worse ), and the Greens? ( Literally Communists! )
Click to expand...

Yes...that sux. I been to Canada many times (truck driver)...beautiful country with plenty of room up north and out west...but the east end is a place I don't miss one bit...I won't be back up there.
 
Yeah, apparently the last owner got it from the British Army and customized it.

___________________________________________________________________

I love this country but if they ban handguns here that is the final straw, and I'll head for Oregon. A handgun ban was a serious issue in the 2006 election and was a close call.
Here's the websites:
http://www.nogunnofuneral.ca/c_aboutus_mission.aspx
http://www.guncontrol.ca/Content/GunControlLaws.html
Have a read over that...

But you're not even allowed any firearm for personal or home defense!
It has to be for hunting (longarms) or collection or target shooting ( longarms and handguns).
Minimum barrel length 105mm for pistols.

There are also specific gun bans, such as banning the Maadi-Griffin .50 BMG pistol by name, even though only one or two were ever built.
Most piston-rifles are banned, etc. Every year it gets a bit tighter.
 
"Energy" is published in gun rags because the numbers look good.
Click to expand...
Energy is frequently used because science tells us that it is a scientifically measurable & calculatable quantity that represents the potential of the bullet to cause damage.

Of course, there are many things that may prevent a bullet from "living up to its potential", so energy is not the whole story. But it's a good place to start, and virtually the only place to start that can be justified from a scientific standpoint.

Momentum is useful in determining the potential of the bullet to penetrate deeply, but again, there is more to the story than that.

My take on this is that any sort of measure of effectiveness that makes one cartridge in the typical self-defense category (9mm, .357Sig, .40S&W, .38spl, .45ACP, etc.) look significantly better or worse than the other cartridges in the class is badly flawed. If it were that easy no one would still be debating the issue.
 
"Toronto gets more dangerous everyday
Anyone would think we're in the USA
We'll be minding our own business
When a coward shoots and kills us
City Council, help us ban handguns today."
~ sung to the tune of " She'll be coming 'round the mountain."

Laughable, but it is extremely serious. If a Liberal Government gets into power there is no Second Amendment to save gun owners, and public opinion is in favour of these bans.
People always say how down south you guys cling to guns and religion, and how Obama will curb the American Gun Culture.

Bowling for Columbine is frequently quoted. Seriously.
 
John...Agreed.

And, you can also use the different formulas to make just about any argument you want...depending on what you prefer to believe.

I like momentum because without penetration...you have nothing (except maybe a big bruise)
 
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