.45acp vs .40 Most Penetration?

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All things being equal the bullet with the highest Sectional Density will penetrate deeper. Looking at Hornady's website a 180 Gr 40 caliber bullet has a SD of .161, a 230 gr 45 caliber bullet, .162. Seems like a tie to me.

If you go up to the 200 gr in 40 caliber it has a SD of .179 and should penetrate deeper.
 
I've heard that the .40 will penetrate pretty well unless right as it begins to hit the target you yell out "More like 'short and weak!' Get thyself a 10mm!" At which point the .40 will bounce off.

In all seriousness, I'm going to guess it has more to do with the load. My gut says a 180gr bullet traveling at normal 4" barrel speeds is going to punch deeper. The fat .45 at normal speeds is going to put more thump on target, but I would guess it would penetrate less.

.45 isn't known to be a punchy round. If it was, why not skip designing the .40 after the Miami shootout and just give the feds 1911s?

I'm over here 9mm land just hoping I don't run into armored bankrobbers or meth-bears.

Honestly both the. 45 and. 40 are great rounds that do the job in different ways.
 
Aren't those rounds designed more for stopping power and not penetration? Penetration isn't desired in an urban environment, especially with civis around.
 
KeyboardCommando said:
Aren't those rounds designed more for stopping power and not penetration? Penetration isn't desired in an urban environment, especially with civis around.
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Stopping power is a myth. A .22 has just as much stopping power as a .45, it all depends where the bullet hits. Penetration is key to stopping targets. My particular use is for black bear protection.
 
Fiv3r said:
.45 isn't known to be a punchy round. If it was, why not skip designing the .40 after the Miami shootout and just give the feds 1911's?
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Actually, and it's an interesting story, when the FBI was testing for a replacement round for the 9 mm which "failed" at the Miami shootout. They did substantial testing of various rounds, bullets and loads. They had already decided on what became the FBI standards for penetration and expansion through barriers in 10% ordnance gelatin. They tested for rounds that would perform as they wanted. It was JHP, as they wanted the penetration.

The agent in charge found that the 180 gr. 10 mm performed as they wanted (it was his Colt Delta Elite they used for the testing). He also found that a 180 gr. jhp in 45 acp also met the criteria. They both penetrated and expanded in the way that the FBI wanted...12-16" of penetration with expansion after passing through select barriers. But the FBI had already ruled out the 1911 and the 45 round due to capacity and the desire for a new round entirely. So they went with the 10mm in a lighter load.

That lasted a hot minute till they chose the 40 S&W, which did the same,in terms of the tests.

But this was with JHP, not ball. That was because the certain jhp could penetrate in a way that met their criteria and expanded to increase the likelihood of damage to the target, and a more brutal wound. It also lessened the potential of ricochets in an urban environment.

With ball various factor come into play. The larger diameter of the 45 means it meets more resistance as it works to penetrate than do smaller diameter bullets (think knitting needle vs. sewing needle). At the same time it's greater mass adds to it's momentum. What the bullet is trying to penetrate is also a factor.

JHP retards penetration in a number of rounds with most jhp bullets. That's why the pics and charts we see of various rounds and calibers all penetrating about the same are specifically because the bullets were built to meet the FBI protocols.

9mm ball tends to penetrate more than either the 40 or 45. That is due to less surface area and energy. But that varies on the bullet type and the load. Energy plays a role as well.

None of this is universal though. Likely with 45 acp and 40 S&W it's a close draw, depending on load, barrel length and what's being hit.
 
I have only a few subjective incidents to base my opinions. During a police firearms training session, our 40cal 165 FMJ shot through IIIa body armor placed on 3d mannequins. We made sure no officers were allowed to carry FMJ after that, only Hydra Shok, in case of a gun take away. The 45acp 230 gr white box would not penetrate the same vests. Shooting into/out of vehicles during training,through glass and body panels, they were about equal, in ricochets and line of sight penetrations.

side note: personally, I feel FMJ from the 40 is adequate for black bear protection.
 
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A 180gr in 40 caliber and a 185gr in 45acp are pretty similar as far as bullet weight and velocity. Results should be pretty close I would think
 
I can't speak for 40 S&W, but when comparing 124 grain 9mm and 230 grain 45acp FMJ rounds, the 45 will penetrate further into soft targets like pumpkins, but the 9mm will penetrate through hard barriers like a cinder block or car door more effective
 
In FMJ ammo, you need to consider bullet shape. Typically, a truncated cone bullet will penetrate deeper than the traditional round nose ball ammo, mostly because it will tend to drive straight, while a round nose will often veer off course. Nearly all .40 S&W "ball" rounds have a truncated cone bullet, but you can find them in .45 ACP. Semi-wadcutters would also be expected to penetrate better than ball rounds.

Here's the theory explained with big game hunting bullets. http://www.gsgroup.co.za/articlepvdw.html
 
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KeyboardCommando said:
Aren't those rounds designed more for stopping power and not penetration? Penetration isn't desired in an urban environment, especially with civis around.
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"Stopping power" isn't a quantifiable thing, but penetration is, and we want to see at least 12" of that in ballistic gelatin for any defensive round.
 
Well, if the guys over on Reddit are to be believed, .40 and .45 will punch through the bad guy, the 12 innocent civilians lined up behind him, and neighbor's house. 9mm, on the other hand, can stop an Abrams with modern ammo, but has never once over penetrated in recorded history. 10mm fits into the whole argument somehow, as well.

All joking aside, I would guess that .40 would penetrate slightly more due to surface area and speed. Think of it like this: If you slap the surface of water, your hand won't go very deep, but will impart a lot of energy to the surface of the water. If you punch the water, though, your hand and a good portion of your arm will be submerged. This is because a fist has less contact surface area than a splayed hand, just as a .40 caliber bullet has less contact surface area than a .45 caliber bullet.
 
FL-NC said:
Our black bear guides in Maine carry 45 autos. I defer to them as the experts.
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.45 Auto is a whole other story. .45 Auto can break ballistic shield glass in the port window after several rounds on the same spot.

@MarkIVshooter Yeah, but penetration can mean different things to different people. The FBI obviously doesn't want armor penetrating rounds, but when you say 'penetration' to someone like me, that is exactly what we think. Penetration is, as another said, about inertia, velocity, momentum and of course the raw surface area of the projectile itself. The Projectile does the work on the target, but the powder it is matched with is what gives it the velocity it needs to make that work happen. Without both, you will get ricochets or weak impacts. We, as a whole, need to go back to designing rounds based on equation, perfectly matching the weight and shape of the projectile with the style of cartridge and the perfect mathematically correct grain load. This is how you achieve the desired round (by hand loading, essentially -- wouldn't have to do that if the manufacturers would demand R&D instead of just produce stuff to 'make money').

It is always nice to remember that stopping a target isn't about penetration or even "power delivered onto target", it is about where you hit them. You'll stop someone a lot faster if you shoot them in the knee cap than if you shoot them thru the arm. Not to mention the face (generally not acceptable practice as a LEO and if you think it is, you're a murderer and not an Officer). However, one is more survivable than the other and depending on your objective, you need to choose wisely where you aim.
 
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jmr40 said:
If you go up to the 200 gr in 40 caliber it has a SD of .179 and should penetrate deeper.
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Bumping your .45 up to 255 grains will get ya back to real close too.

Underwood makes a nice 255 grain hardcast I use in the woods if Im not carrying my 10mm.
 
JR24 said:
Bumping your .45 up to 255 grains will get ya back to real close too.

Underwood makes a nice 255 grain hardcast I use in the woods if Im not carrying my 10mm.
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The higher the grain count, the harder the felt recoil and the slower the follow up shot. Never forget that.
You want the proper grain to match your chosen projectile otherwise you're just putting extra recoil into your hand/arm that you don't even need, which only gives you more muzzle rise and thus less accuracy.

So, if a .40 with 200 grains can do what a .45 with 255 grains can do, I'd choose the .40 almost every time. This is why James Bond carried a .380, he could put all 8 shots right where he wanted them -- super accurate with little to no recoil. It is about where you are shooting, not how fast or how hard it hits, or whatever.
 
KeyboardCommando said:
The higher the grain count, the harder the felt recoil and the slower the follow up shot. Never forget that.
You want the proper grain to match your chosen projectile otherwise you're just putting extra recoil into your hand/arm that you don't even need, which only gives you more muzzle rise and thus less accuracy.

So, if a .40 with 200 grains can do what a .45 with 255 grains can do, I'd choose the .40 almost every time. This is why James Bond carried a .380, he could put all 8 shots right where he wanted them -- super accurate with little to no recoil. It is about where you are shooting, not how fast or how hard it hits, or whatever.
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Naturally, that's like ammo selection 101. But also not the question asked in the OP.

FWIW I still shoot even heavy .45 faster than .40 due to recoil characteristics and, likely, my preference for the round.
 
JR24 said:
Naturally, that's like ammo selection 101. But also not the question asked in the OP.

FWIW I still shoot even heavy .45 faster than .40 due to recoil characteristics and, likely, my preference for the round.
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Absolutely, it all depends on personal preference and of course the operation of the equipment you're using. Those two factors really do have a lot of impact on what calibre and firearm people choose to use.
Obviously, someone who is 7 foot tall and 300 pounds of muscle will think the 10mm is clearly the best choice, but someone half that size will disagree wholeheartedly.

To answer the OP's question, if the rounds are the same -- the .40 will penetrate further because it has less surface area that causes resistance, just as another poster already mentioned. .40 will win unless you put more grain on the .45 but that isn't the circumstances of the question, so the answer to the OP's question is .40. It also only mentions FMJ, so there is no need to talk about different kinds of projectiles and their various ways of penetrating or impacting.

Furthermore, This has nothing to do with the 'meta' of one calibre simply being 'better' than the other -- it is all just physics, folks.

Maybe this metaphor will work (maybe not): Think of the .40 as a Porche, it's fast and can do turns great but loses out in a straight run. Think of the .45 as an american muscle car, loses out in the turns but does straight speed runs really well. They are different beasts and are applied and used in different ways. There are additional factors of the equipment itself that play into which is chosen based mostly wholly on personal preference.
 
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KeyboardCommando said:
The higher the grain count, the harder the felt recoil and the slower the follow up shot. Never forget that.
You want the proper grain to match your chosen projectile otherwise you're just putting extra recoil into your hand/arm that you don't even need, which only gives you more muzzle rise and thus less accuracy.

So, if a .40 with 200 grains can do what a .45 with 255 grains can do, I'd choose the .40 almost every time. This is why James Bond carried a .380, he could put all 8 shots right where he wanted them -- super accurate with little to no recoil. It is about where you are shooting, not how fast or how hard it hits, or whatever.
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40 S&W in the heavier flavor has felt recoil equal to 230 grain 45acp for most people. It's just a different type of recoil. 45 is tends to be easier to shoot accurate rapid followup shots for most average shooters from what I've seen because there is less muzzle flip.

Also, James Bond carried a little Beretta-418 25acp before later upgrading to a PPK in 32acp.
 
Bigmike79 said:
40 S&W in the heavier flavor has felt recoil equal to 230 grain 45acp for most people. It's just a different type of recoil. 45 is tends to be easier to shoot accurate rapid followup shots for most average shooters from what I've seen because there is less muzzle flip.

Also, James Bond carried a little Beretta-418 25acp before later upgrading to a PPK in 32acp.
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True, although the various Bond's did carry many different kinds of pistols over the decades. Generally it is those small pocket pistols for accuracy, conceal-ability, weight and round count.
You can carry more .25/.32/.380 than you can .40 or .45 and they weigh less. Of course this is important for an agent but not so much for the average joe on the street, I suppose. I still like the semantics of it.

The follow up of the .45 is probably due to the velocity and extra grains. That means more velocity and quicker travel time, shorter barrel exposure, faster time to target. Less time in the barrel and faster overall traveling time means faster consecutive shots. Where the recoil/muzzle rise comes into play is from the grain count, that is where the accuracy loss is: in the muzzle rise. What I mean by follow up shots is not necessarily how fast you can shoot the bullets with the gun, but rather how many bullets you are putting on target or in the same bullet hole. With less recoil and less muzzle drift/rise you can put more follow up shots on the same spots, you can't do that with a .40 or .45 because the recoil/muzzle rise affects accuracy directly. With those pocket pistols, you can put the whole magazine in the 6 ring in a few seconds, much harder to do with a heavy .45. Of course this also depends on your physical ability and endurance, as well. A smaller person will be able to use a .380 or .32 much better than a .45 and a larger person might think those are too small but the reality is those pocket pistols are just right for special agents needs. Every thing is a matter of personal circumstances and preference more so than actual 'technical superiority'. Things are designed for certain effect and to fit a certain application or fill a need. Stuff in the world hasn't been made "to be better" for about 60 years now (since all the old guys are complacent with the old tech they grew up with, they see it as fine for us and have blocked all technological progress. We live in a monopoly so old people can make "money" and feel good and important -- nothing is actually technologically progressed with a direct tie to corporate control. This is why you don't see Individuals designing firearms any more and why the government is trying to make it criminal. You can't gain control without complacency and dead ends, for, if someone can just improvise or innovate beyond your means of control then the reigns don't work and the crooks don't like that.
 
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jmr40 said:
All things being equal the bullet with the highest Sectional Density will penetrate deeper. Looking at Hornady's website a 180 Gr 40 caliber bullet has a SD of .161, a 230 gr 45 caliber bullet, .162. Seems like a tie to me.

If you go up to the 200 gr in 40 caliber it has a SD of .179 and should penetrate deeper.
Click to expand...

Yep, same SD and ME. Both subsonic as well.

The .40 does it w/ a 4" Bbl., though.




GR
 
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