# Caliber Wars: Cop Weighs In On Department’s 9mm vs. .40 Duty Gun Decision



## BackyardCowboy (Aug 27, 2014)

Caliber Wars: Cop Weighs In On Department's 9mm vs. .40 Duty Gun Decision - The Truth About Guns


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## TheReaper (Nov 14, 2008)

I would prefer an M&P SA chambered in 357 Sig.


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## denner12 (Oct 14, 2017)

I like G-22's


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## Steve M1911A1 (Feb 6, 2008)

From the story to which we are linked: "...Sgt. Grennes reportedly then got into more detail regarding his department's decision...'The difference between the 9mm and the .40-caliber guns,' he explained, 'is one of cartridge ignition pressures. The 9mm has a long, low, smooth ignition impulse, while the .40 has a short, sharp, abrupt ignition impulse.'..."

Although the story follows this assertion with a rebuttal of it based entirely upon chamber-pressure figures, my experience agrees more with that of Sgt. Grennes's, rather than with the simplistic-seeming rebuttal.

I used the .45 ACP cartridge extensively, firing 9mm only when it was required by the rules of the game. In so doing, I always noted that the softer, long-duration recoil impulse of the .45 ACP cartridge seemed subjectively much easier to handle, control, and absorb than did the quicker, sharper, jab-like impulse of the 9mm (assuming similar-weight pistols, of course). And there's more to it than mere chamber pressure, although that is a contributing factor.

I'm _not_ saying that the 9mm and the .45 ACP are similar to each other, when compared to the .40 cartridge.
Instead, I'm averring that each cartridge's recoil profile is different from all others, and that comparisons among the recoil behaviors of various cartridges are very subjective.
But I'm also saying that although these comparisons are subjective, they are neither less true nor less valid because of their subjectivity. The shooter feels what he feels.

(I have absolutely no experience with the .40 cartridge. Instead, I must rely on subjective comparisons made by frequent users, for instance Sgt. Grennes.)


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## pblanc (Mar 3, 2015)

I have a lot of experience with .40 S&W. I do believe that .40 S&W produces greater rearward slide velocity and a "sharper" recoil than either 9 mm Luger or .45 ACP even though the calculated recoil of .45 ACP is greater. Maximum case pressure limits do not define how quickly that maximum case pressure is achieved.

357 SIG achieves a higher maximum case pressure than .40 S&W (40,000 as opposed to 35,000 psi) and generates significantly greater kinetic energy (with about the same momentum) yet many feel that 357 SIG has less perceived recoil than .40 S&W.

But Sgt. Grennes displays his ignorance of ballistics when he refers to .40 S&W as "a bigger, faster bullet" than 9 mm. Bigger yes. Faster, almost never.


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## FindANewSlant (Sep 4, 2018)

Having fired both, along with .45 ACP, several times (but not to mastery), I would say I'd prefer a 9mm if it comes to a shootout with bad guys. the 9mm is very easy for me to control.


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## Tangof (Jan 26, 2014)

Caliber wars have been going on for decades and will continue until a whole different arm is created. My great Uncle's, both LEO's, argued about the stopping power of the .32 S&W Long versus the .32 Colt New Police. I'm pretty sure they were identical. My own experience was firing the .40 in the S$W and Glock when the U.S. DOJ was trying to decide what caliber / handgun they were going to adopt. My personal, and I stress that it is a personal opinion, is that the ,40 wasn't as accurate as the 9MM and recoiled much more sharply than the .45 in like handguns. I've spent a lifetime shooting handguns of all types and owned a large number of different caliber revolvers and pistols but never once felt the urge to buy a .40 of any make. For what it's worth, I can't recall one student in the eighteen years I was a firearms instructor that shot the .40 S&W better than they did a 9MM in the same type handgun.


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## BigHead (Jul 5, 2015)

It seems like a tempest in a tea pot to me.


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## Steve M1911A1 (Feb 6, 2008)

BigHead said:


> It seems like a tempest in a tea pot to me.


Yup.
It always is.


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## Philco (Apr 17, 2012)

I have experience shooting the 9mm, 40, and .45ACP. My experience was that the .40 had a sharper recoil that produced more kick and muzzle flip than either of the other cartridges. I have a 9mm as my daily carry but have previously carried a .45 pistol. I do not own or desire to own a .40 caliber pistol even though I see good deals on police trade ins posted regularly.


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## pblanc (Mar 3, 2015)

I don't choose .40 S&W for small, light pistols but it is not difficult to shoot from mid or full size, all-metal pistols once you become accustomed to the recoil characteristics. I tend to shoot it more accurately than 9 mm Luger even when I am shooting 9 mm with a large, all-metal pistol like the Beretta 92 FS.


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## crewchief (Jul 25, 2018)

What was it,,,, anything the nine can do the 40sw can do better!!!! Yup the 40sw getting the whack cuz most of our girls going into law enforcement can't qualify with the 40! Forget the bull about the nines bullets are better now. The 40sw bullets are also better now....... I've tried to let some women shoot my p226 40 and most say no, usually when they do shoot it a couple of shots and its handed rite back to me!!


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## TheReaper (Nov 14, 2008)

My wife can handle my M&P.40 really well but she hates the Sigma ve .40.


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## Tangof (Jan 26, 2014)

Did anyone like the Sigma series? I don't remember anyone who bought one in no matter what caliber liking them.


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