.40 penetration vs .45 penetration

The reason I ask is why do law enforcement use .40 over .45?

If .40 does not penetrate better than .45 why not just use .45?
 
If .40 does not penetrate better than .45 why not just use .45?
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If penetration was the main factor in deciding on a certain caliber, I imagine they would use .45acp.

More penetration is not always a good thing... at least when it comes to guns :)
 
The reason I ask is why do law enforcement use .40 over .45?
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Short answer

Most 45 ACP magazines are limited to 7 or 8 rounds, 6 for a compact 45.

Most 40 cal magazines hold 10 or 12 rounds.

Anymore than that they would either have to have an unwieldy extended magazine protruding from the butt of the gun or go double stack taking it out of the reach for shooters with smaller hands.

The bullet is faster and shoots flatter than a 45 but at most combat ranges this is a moot point.

The telling point is a overall 25% hit rate by officers in shooting situations and more ammo is a plus under those circumstances.
 
Because what happens when you miss? Or when the bullet passes through the intended target.

Police don't operate in a war zone they work in a civilian environment. They are there to protect & server not kill everyone perceived as a threat.

It's a fine line balancing enough firepower to do the job and doing more damage then is acceptable.
 
I think it would be interesting if a police department adopted the FN 5.7 as a duty gun. Twenty rounds of firepower is pretty impressive. Most armed encounters do not include body armor, and body armor would defeat the other commonly carried rounds anyway.

I hope this is not going to turn into another caliber war, but the .45 acp round is somewhat out dated. By that I mean operating pressures are low by today's standards. The .45 acp operates at 21,000 psi while the .40 S&W operates at 35,000 psi. I'm sure the .45 acp can be pushed way hotter in well built, modern firearms, but ammo manufacturers won't due it due to a huge liability of the ammo blowing up in an older (unfit) gun. Of course the smaller diameter and consequently greater mag capacity are also a good reason for the .40 S&W's acceptance.

Glock created the .45 GAP to make the .45 round "more size efficient". Operating pressures are similar and velocities are also comparable. While Glock could have easily designed the round to out perform the .45 acp, they probably limited the power to keep recoil acceptable for the majority of shooters.

If I recall correctly, the .40 S&W was created after the perceived failure of the 9mm during the Miami Shootout. The 10mm was adopted by the FBU, but it was dropped because it had too much recoil. Since the extra power wasn't needed, the case was shortened. That was the birth of the .40 S&W.
 
Super-Dave,

Most .45 ACP pistols are NOT 13 rounders. The 1911 is probably still the most popular .45 acp pistol and the vast majority of them are of the single stack 7 or 8 round variety. Many members on this forum are not that keen on Para Ordnance due to their spotty production. Many of the larger double stack .45 acp pistols are too large for many shooters to hold comfortably. I don't think there are any double stack .45 acp pistols that can be easily concealed. I believe that is the reason for Glock creating the Glock 36, which has a single stack 6 round magazine.
 
the .45 acp round is somewhat out dated. By that I mean operating pressures are low by today's standards. The .45 acp operates at 21,000 psi while the .40 S&W operates at 35,000 psi.
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Don't forget that comparing operating pressures between two different calibers is problematic. Pressure is force per square inch, and a .45 ACP bullet has 27% more cross-sectional area for the force to act upon than a .40 S&W bullet.

Comparing kinetic energy or momentum between dissimilar calibers is probably fairer, but that debate has been raging for years as well.
 
ScottRiqui said:
Don't forget that comparing operating pressures between two different calibers is problematic. Pressure is force per square inch, and a .45 ACP bullet has 27% more cross-sectional area for the force to act upon than a .40 S&W bullet.

Comparing kinetic energy or momentum between dissimilar calibers is probably fairer, but that debate has been raging for years as well.
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Comparing operating pressures between cartridges is certainly not problematic. Take a look at this SAAMI chart and you will see that most modern handgun cartridges operate in the 30,000+ psi range. Only the older cartridges such as .38 special (17,000 psi), .44 Special (15,500 psi), and .45 Colt (14,000 psi) operate with lower psi. Any cartridge by itself lacks strength and would rupture if detonated outside a barrel. The strength of steel has improved greatly and better designs allow guns to operate at much higher pressures. If you look at the breech of older 1911 pistols, you will notice that the breach is barely thicker than the barrel. Many modern semi-autos could handle much higher pressures with their thicker squared off breaches (Sigs, Glocks, H&Ks, etc...). Even the 1911s can handle higher pressures with thicker barrels and the proper springs as proven by the .400 Corbon which operates at 29,000 psi.
 
You're right - I should have said that comparing operating pressures in order to use them as some kind of measure of effectiveness is problematic. A lower pressure acting on a larger bullet can impart the same total amount of energy as a higher pressure acting on a smaller bullet.

While it's true that modern design and metallurgy would allow much higher-pressure versions of the older cartridges you named, but even if the consumers could keep the versions straight and not blow their guns up, is there really a need?
 
ScottRiqui said:
You're right - I should have said that comparing operating pressures in order to use them as some kind of measure of effectiveness is problematic. A lower pressure acting on a larger bullet can impart the same total amount of energy as a higher pressure acting on a smaller bullet.

While it's true that modern design and metallurgy would allow much higher-pressure versions of the older cartridges you named, but even if the consumers could keep the versions straight and not blow their guns up, is there really a need?
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I am certain that the operating pressure of the .45 acp could be much higher (at least 35,000 psi) in a properly designed handgun. As you mentioned, there probably is little need for it. Handguns certainly are capable of much more power than a .45 acp (as evidenced by all the handgun rounds that are more powerful than the ,.45 acp). The problem is the recoil tolerance of shooters. I believe the .40 S&W produces as much power (if not more) than the .45 acp in a more size efficient package (greater mag capacity for the same length mag).
 
I believe the .40 S&W produces as much power (if not more) than the .45 acp in a more size efficient package (greater mag capacity for the same length mag).
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I'm not hating on the .40 S&W (it's what I use in my carry gun), but "power" is a vague concept when it comes to handgun cartridges. You can measure kinetic energy and momentum easily enough, but as I said earlier, there's an eternal debate regarding which is more important. Some .40 S&W loads have more kinetic energy than some .45 ACP loads, but .45 ACP has consistently higher momentum.

Regardless, I don't feel underarmed carrying a .40 S&W.
 
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G&A TV did a brief demo on car doors tonight and even 38's out of a snubby penetrated the door. The 12g slugs were rude.

Personally, I don't even feel under gunned with a 9mm - my Hi-Power is in truck rotation currently. But, I shoot 1911's in 45acp much better than any other gun I've shot. If I was a police officer maybe round count would be more important and I'd learn to shoot what I was allowed to carry. If I need more than 7-8 rounds then I should have had my AR or M1 carbine closer.

tjg
 
But most modern .45 hold at least 13 rounds now.
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The only way one could arrive at such a conclusion is to stretch the definition of "modern .45"s. Most .45 pistols currently on the market don't hold that many rounds.
 
I would be very interested to see how heavy a bullet the .40 S&W could push. I know it is limited by case capacity since the extra weight of the bullet would have to come from a longer bullet. If hotter burning powders could be used, I think the .40 S&W could duplicate the .45 acp's ballistics. Winchester loads a 185 grain Silver Tip bullet that travels at 1000 fps. That is pretty close to the typical velocities of 180 grain .40 S&W bullets.

I'm certain the 10mm can easily duplicate the .45 acp's ballistics, although that would be downgrading it. The most common 10mm rounds are 200 grain bullets that travel at 1300 fps. The heaviest ones I have seen push a 230 grain bullet at just over 1100 fps. The hottest .45 acp +P in 230 grain I was able to look up doesn't even hit 1000 fps and the hottest .45 acp +P in 200 grain just broke 1100 fps.
 
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Back to the original question, I know from first hand experience that a 230 grain FMJ .45 ACP will out penetrate by a considerable margin a 180 grain FMJ .40 S&W shot into dry phone books. But, that is just one material, and one bullet style. I suspect that the higher velocity and smaller frontal area of the .40 would enable it to punch through thicker sheet metal than the .45. There are so many variables that enter into penetration that it is impossible to make a blanket statement. When it comes to penetration in flesh, higher velocity does not necesarily mean more penetration, in fact, often a projectile at higher velocity will penetrate less.
 
Super-Dave

But most modern .45 hold at least 13 rounds now. So I see no advantage.
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You must have missed post #5.:rolleyes:


#5

Short answer

Most 45 ACP magazines are limited to 7 or 8 rounds, 6 for a compact 45.

Most 40 cal magazines hold 10 or 12 rounds.

Anymore than that they would either have to have an unwieldy extended magazine protruding from the butt of the gun or go double stack taking it out of the reach for shooters with smaller hands.

The bullet is faster and shoots flatter than a 45 but at most combat ranges this is a moot point.

The telling point is a overall 25% hit rate by officers in shooting situations and more ammo is a plus under those circumstances.
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You must have missed post #5.
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Super-Dave

But most modern .45 hold at least 13 rounds now. So I see no advantage.
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No I doubt JohnKSa missed the post. I agree with his statement.
The brand I know that holds 13 rounds is the XD, XDM. To get that kind of count in a 1911 you have to go to a double stack. G30 is 10+1 G36 is 6+1 and maybe our other members can add what they know about the other polymer gun makers as far as round count is concerned
 
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