40 vs 45

Better get 'em both...

Instead of listening to opinion, hyperbole and anecdotal evidence, you can now see real bullet tests from ammoguide.com.

This graph represents the most common bullet weights for self-defense. I did not add bullets with exceptionally low bullet weights so as not to skew the results.

The 9mm and .40 S&W show data from a 4" barrel and the .45ACP shows 5" barrel data. The .45ACP holds a 1" advantage in barrel length due to a lack or 4" barrel data for that caliber.

Draw your own conclusions.

.40S&W is a poor substitute for .45acp.

The muzzle energy advocates are always forgetting things like momentum and the size of the bullet.

.40S&W is a poor substitute for .45acp.

The muzzle energy advocates are always forgetting things like momentum and the size of the bullet.

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Since you seem to believe that drivel, I suggest that you sell your handguns and simply throw your big bullets.

Better yet... If you could throw your 2 pound gun at 70 MPH, you could achieve devastating ballistics.
2 pound gun = 14,000 gr
70 MPH = 102.667 fps
Energy = 329.39 ft/lbs

Ballistics is an equal measure of projectile weight and projectile velocity. That is why tiny .22 caliber bullets fired at 3,300 fps from the AR15/M16 platform are so deadly.

Since you seem to believe that drivel, I suggest that you sell your handguns and simply throw your big bullets.

Better yet... If you could throw your 2 pound gun at 70 MPH, you could achieve devastating ballistics.
2 pound gun = 14,000 gr
70 MPH = 102.667 fps
Energy = 329.39 ft/lbs

Ballistics is an equal measure of projectile weight and projectile velocity. That is why tiny .22 caliber bullets fired at 3,300 fps from the AR15/M16 platform are so deadly.

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Gglass.. bravo sir. BRAVO. I am still laughing at the 2lb thrown gun thing. That made my day.

gglass said:

Since you seem to believe that drivel, I suggest that you sell your handguns and simply throw your big bullets.

Better yet... If you could throw your 2 pound gun at 70 MPH, you could achieve devastating ballistics.
2 pound gun = 14,000 gr
70 MPH = 102.667 fps
Energy = 329.39 ft/lbs

Ballistics is an equal measure of projectile weight and projectile velocity. That is why tiny .22 caliber bullets fired at 3,300 fps from the AR15/M16 platform are so deadly.

Click to expand...

Well that's a poorly worded arguement that doesn't even bother to address what I said. Since you obviously don't even know what the definition of ballistics is, please navigate your internet browser toward an online dictionary or wiki, that might help you a bit!

Since you brought it up.. About the 5.56x45mm.. No, I'm sorry to say you've got that completely wrong as well. The reason why .22 caliber bullets fired at 3100fps are so deadly is because when they hit a target at over 2700fps, they fragment upon impact, but still have sufficient mass to cause massive tissue disruption. Why did you respond to me when you didn't even address what I said and brought up more energy "drivel"?

Ok ok ok! (voice of Leo Getz as played by Joe Pesci)

If we're discussing the kinetic energy of the rounds, consider the source of the numbers on energy.

The equation relating mass and velocity to kinetic energy is K.E.=0.5(m)(v^2).

Now, based on this relation, which factor do you think has a greater influence on kinetic energy of a system?

If your answer is velocity, you are correct. That is true because the velocity term is squared. It increases at a non-linear rate. That's what exponents do.

Now, if we consider the base weight of a .40 (180gr) and a .45(230gr), and the .40 is moving at 1091 ft/s and the .45 is moving at 930 ft/s, square each of these terms. for the .40, v^2=1,190,281 and .45 v^2=864,900. The difference in weight between these two bullets is about 3 grams. Have you looked at how small a gram is lately? It's not a whole lot.

Now, since I've proven that the kinetic energy between the two most common loadings for each caliber shows the .40 to be higher, let's now discuss how this is transferred to the unlucky S.O.B. who gets in the way.

Assuming both are reliably expanding hollowpoint bullets moving at the given velocities, and both hit center mass and behave as they are engineered to (expand and stop inside the body), the energy gets dumped entirely into the person. That energy is what is responsible for tearing up their insides, making them bleed out, and die from their injuries. This puts the .40 ahead of the .45.

Someone earlier made the mistake of saying the .45 was a half inch bigger than the .40. I laughed. I laughed hard. We're talking 5 hundredths of an inch. Take out your ruler, look at one inch, and try to break it up into a hundred little pieces. Pretty small, right? Now, envision 5 of those little pieces, and that's the difference in diameter. Not a whole lot of difference.

I know a lot of you have nostalgic feelings about the .45, but the numbers are on the side of the .40. We're not talking about a HUGE difference, but it's still a difference.

By now you're probably about to post "SO I BET YOU THINK THE 9MM IS A LIGHTNING BOLT THROWN BY ZEUS, DROPPING ANYBODY WITH ONE HIT!" Before you make a fool out of yourself and make me post again, this is why the 9mm has a "shortfall".

The 9mm is typically moving at such a velocity that it just zips right through. If it does, you have leftover kinetic energy that does not get transferred to the target. If it does stop, then that's excellent. That will probably be a very disabling hit.

Excellent post Bovice. But because velocity is squared (as you mentioned), it has more of an effect on energy calculations than does mass. This is the exact reason why kinetic energy is not a good real world indicator of performance. There are 50-64gr. 9x19mm loads made by manufacturers such as Magsafe that have massive amounts of energy, but very poor terminal performance (by design).

The 9mm is typically moving at such a velocity that it just zips right through. If it does, you have leftover kinetic energy that does not get transferred to the target.

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I love the idea that a bullet that makes two holes does less damage simply by not stopping within the target. (Bullet design issues aside) That's like saying the 9mm could be more deadly if you fired it at lower velocity. "Dang, it went right through him! Let's make it less powerful so it'll do more damage!"

Bovice said:

The 9mm is typically moving at such a velocity that it just zips right through. If it does, you have leftover kinetic energy that does not get transferred to the target. If it does stop, then that's excellent. That will probably be a very disabling hit.

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Leftover kinetic energy in this scenario would make very little difference to the damage done unless we are talking of rounds with enough energy to produce hydrostatic shock damage, then there might conceivably be some loss of effectiveness. Otherwise, in making a hole right the way through and assuming it expanded, then it's done more damage than had it come to rest only part way through.

PS What evidence is there that a 9mm round (I assume we are talking hollow points here) typically "zips right through"? I've heard it said before but not seen any data to that effect.

that brings up another point in the argument. Are two holes better than one? If you were to shoot someone and the bullet passed completely through a vital area, they are now bleeding from two places. Since the diameter of the bullets of each respective caliber are not greatly different in terms of the hole they make on a human body because the cavitation track made by the bullet will close itself, two holes would mean more bleeding, more bleeding means a faster drop in blood pressure, a large drop in blood pressure with no treatment means death.

I am a .40 fan. Now with that being said, 45 has a greater momentum than 40. Momentum = mass x velocity. This is equates to stopping power. Now the real question arises. What is more important in dealing with ballistic performance: momentum or energy?

Give me a 9mm and I will be happy. I like the .40 S&W as well as the .45 ACP but it really depeneds on the platform of weapon I am shooting.

LeontheProfessional said:

I am a .40 fan. Now with that being said, 45 has a greater momentum than 40. Momentum = mass x velocity. This is equates to stopping power. Now the real question arises. What is more important in dealing with ballistic performance: momentum or energy?

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Great question. I've attempted to explore it with a simple calculation based on conservation of energy and conservation of momentum. All the details are in the calculation below. From this calculation, I conclude:
(1) Penetration depth is related to energy. A more energetic bullet will penetrate deeper.
(2) Penetration time is related to momentum. The heavier the bullet (the greater the momentum), the longer it will take to penetrate to its final depth.

So given two bullets of different masses but with equal impact energy and equal cross-sectional area, both bullets will penetrate to the same depth but the heavier bullet will take longer to do the penetrating. I would guess that a slower penetration rate would decrease the effectiveness. So a light fast bullet should be more effective than a heavy slow bullet (energy and cross sectional area being the same).

So, in answer to the question, I think stopping power is mainly about the energy and if you can achieve the energy in a lighter bullet, that will be more lethal than achieving the same energy in a heavier bullet of the same caliber. Of course, this calculation is highly idealized and neglects many real life factors.

Unless of course the slower, larger bullet does more tearing damage rather than cutting damage and thus spreads the disruption of nerve endings and blood vessels farther outside of the bullet path.

The other thing to consider is that as long as your hollowpoint technology opens fully at both the faster and the slower velocities, with a heavier bullet you have more material to potentially open a larger permanent wound channel.

Muzzle energy is an illustrative measurement but it is not the sole indicator nor does it determine terminal ballistic effectiveness. Perhaps something new like opened bullet diameter * velocity * mass * time to full expansion / bullet capacity.

Any way you look at it, both are effective, they clearly go about being effective in completely different ways.

I've seen the damage of both and I would go with the .45 acp anyday over the .40 S&W.

LawofThirds said:

Unless of course the slower, larger bullet does more tearing damage rather than cutting damage and thus spreads the disruption of nerve endings and blood vessels farther outside of the bullet path.

The other thing to consider is that as long as your hollowpoint technology opens fully at both the faster and the slower velocities, with a heavier bullet you have more material to potentially open a larger permanent wound channel.

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Please bear in mind that my intention was to look at the influence of energy and momentum so I kept other factors the same to avoid too many variables. E.g. I assumed the same expanded cross sectional area for both bullets. Also, to keep the energy the same in both calculations, I had to reduce the velocity of bullet 2 to an unrealistically low level. These calculations are not intended to compare actual real world bullets because in a more realistic comparison additional parameter changes would have to be taken into account.

LawofThirds said:

Muzzle energy is an illustrative measurement but it is not the sole indicator nor does it determine terminal ballistic effectiveness. Perhaps something new like opened bullet diameter * velocity * mass * time to full expansion / bullet capacity.

Any way you look at it, both are effective, they clearly go about being effective in completely different ways.

Click to expand...

Experimental data would be needed to produce the kind of empirical correlation that you suggest.

The calculation was enough to suggest to me that energy is the dominant factor and that it could be marginally better to achieve the required energy with a lighter faster rather than a heavier slower bullet. I could be way wrong because this is such a simplified calculation but that's the tentative conclusion I draw from it.

that brings up another point in the argument. Are two holes better than one? If you were to shoot someone and the bullet passed completely through a vital area, they are now bleeding from two places.

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As it happens, this is an area long on conjecture and low on hard data for obvious reasons. But there's a fairly good analysis of this question here. There are two chief schools of thought on the matter. The "absorbers" argue that a bullet that passes through a target is carrying residual energy with it - which is bad because you want all the energy of the projectile to affect the target. Ideally, the round would come to a stop just as it breaks the skin on the back. Payload delivered.

The "exit wound" school notes that a small entry wound is usually dwarfed by the large hole on the other side, and more trauma and bleedout results from a good healthy rip-through. As noted in the article, all this activity slows the bullet down and alters its trajectory, so there isn't much danger posed to those downrange.

If the police statistics are at all representative (and I think they are), then on average in a gunfight you'll land about 1 in 5 shots, the others going astray. This suggests that in a populated environment you'll be better off with ammo that deliver its energy quickly on expansion, because you're fully responsible for any rounds that miss.

Shockwave
Excellent article, I saved that one on file. Thanks

Better yet... If you could throw your 2 pound gun at 70 MPH, you could achieve devastating ballistics.
2 pound gun = 14,000 gr
70 MPH = 102.667 fps
Energy = 329.39 ft/lbs

Click to expand...

You know the average claw hammer weighs only 16oz? And a baseball weighs only 5 oz, and the average person can't throw one even 50mph? You know what a slung shot is, and how lethal they are?

If anyone out there could actually throw a 2 pound steel ball (or maybe hatchet/hammer/spear?) @ 70mph, 12 times in ten seconds with 1 hand, be able to initiate and release a throw as fast as one could pull a trigger, maintain 6" groups at 21 feet, and could carry around 12 of 'em, that would indeed be devastating.

So given two bullets of different masses but with equal impact energy and equal cross-sectional area, both bullets will penetrate to the same depth but the heavier bullet will take longer to do the penetrating.

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1. What makes you think that a bullet will do more damage if it decelerates faster?

2. Wrong about equal penetration. In this particular scenario, the lighter bullet might not penetrate as far. It will impact at a higher speed, creating a bigger shock wave.

If the target is small/delicate enough, the shock wave will cause the target to explode into little pieces, i.e. a small fruit, coke can, squirrel hit by a .223 hollowpoint. If the target is larger and tougher, then the shock wave is just wasted energy.

On at the other extreme, too big and slow, and you end up with a hammer. It might break some bones, but it won't penetrate as far. There's obviously a compromise that takes place. I think the .40 might be the best compromise out there, for many people.

My opinion is that .40SW is a bit more size-efficient as a cartridge, with similar SD performance (using modern HP) and recoil. So it has the real advantage of greater capacity.

The only place where .45 ACP really holds an edge is with FMJ. What some people don't realize is that the "measly 0.05 inch bigger bullet" actually has 27% greater cross sectional area than the .40 SW. Yeah, that's right. Stop breaking rulers into little bits and try picking up a calculator. Keep calling a 27% difference insignificant, if you don't want to be taken seriously! (0.452*0.452)/(0.4005*0.4005)=1.274

ad hoc mathematics..

velocity is not static.. your mathematics do not take that into account.. nor does it take air densities into account.. nor coefficient of drag on the projectile..

and the other variable is the powder charge.. even though manufactured cartridges are closely monitored, there is a minute variable in the powder charge from one cartridge to the next.. and if your going to rely on mathematics, this has to be taken into account..

one .45 cartridge may be loaded and exceed the stated .40 cartridge for energy.. and the reverse can be true also..

and all this talk about velocities and .22s... i guess the real winner is the 5.7x28.. LOL..

.40S&W is a poor substitute for .45acp.

The muzzle energy advocates are always forgetting things like momentum and the size of the bullet.

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I'll concede that the .45 is larger in diameter.
But only by .05".
You'll have to decide for yourself how significant that size difference really is.

But the momentum argument is not so clear cut.
Most of the online ballistics are generated using .40 rounds shot from a 4" barrel handgun and .45 rounds shot from a 5" barrel handgun.
I've yet to see ballistics of a .45 shot from a subcompact pistol vs a .40 shot from a subcompact....say a 3" to 3.5" barrel.

GLOOB said:

1. What makes you think that a bullet will do more damage if it decelerates faster?

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I think you are referring my post #139 with its attached calculation. In my (highly idealized) calculation, two bullets of the same cross-sectional area and same impact energy were found to penetrate to the same depth but the travel time was found slightly longer for the bullet with the higher mass, i.e. its deceleration rate was less. I don't know what is the influence of the deceleration rate on the human body or even if it has any influence.

GLOOB said:

2. Wrong about equal penetration. In this particular scenario, the lighter bullet might not penetrate as far. It will impact at a higher speed, creating a bigger shock wave.

If the target is small/delicate enough, the shock wave will cause the target to explode into little pieces, i.e. a small fruit, coke can, squirrel hit by a .223 hollowpoint. If the target is larger and tougher, then the shock wave is just wasted energy.

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It was a premise in my calculation that the two bullets had the same penetration depth. That was the starting point for my calculation not the conclusion. My model didn't include any shock wave effects. My calculation had the limited purpose of exploring the question of which was more important, energy or momentum. The model suggested to me that energy controlled the penetration depth and momentum controlled the penetration time. Penetration depth is obviously important but I don't know whether or not penetration time is important.

Both are great rounds, but I prefer .45.

Reading people talking about the 9mm having more capacity, I don't spray and pray, I am pretty good at hitting what I aim at without expelling a butt load of rounds.