.40 S&W: better than 9mm?

I know there’s lots of debate about the .40 vs. the 9.
But I ask because I was thinking about giving my Security 9 to my dad for a carry pistol (it’s plenty reliable; I think the new mag is causing it to jam though; gotta figure that out at the range sometime) and buying an S&W M&P Shield 2.0 compact in the .40 caliber. I like the idea of a .40 because it’s that in-between cartridge: not as light as a 9mm but not as heavy as a .45 ACP.
Now before I do decide to get the gun I would shoot a .40 caliber handgun first but I was just curious about what your guys’ thoughts on the topic are.


Great questions, Luke! I just had a similar discussion with a first-time gun buyer this weekend! They really wanted a 45 for the stopping power. I brought up a few points for them to consider:

  • Cost of the ammo for training
  • Cost of the ammo for carry
  • Size of the gun for carrying
  • Recoil of the larger caliber from a smaller size carry gun

I would highly recommend shooting the gun you’re interested in, in the calibers your considering. That should help you get a better idea of what you really want to carry and what feels good to shoot.

Am I missing any things to consider, @45IPAC?


@Dawn, there is one other thing to consider and, that is the service life of the gun. Most .40 cal hand guns are actually 9mm guns converted to .40 and, have a greatly reduced service life because of that. Most of the .40’s that were designed specically for that round are all metal with the exception (that I know is thus far) of the H&K USP.

An interesting side note is that pretty much the only reason that Smith and Wesson designed the .40 S&W round was at the request of the FBI.


I didn’t know that most .40s were converted from 9mm which reduces the life of the gun. That’s an interesting note that you brought up.

As a general rule of thumb (meaning that there are exceptions). A way to guestimate if the handgun was designed for .40 S&W is to look up the history of that model and, see which caliber was on the market first.

From my understanding the bulk of the service life reduction involves the frame. I would venture a guess that if you have one that the frame is not serialized you can just get a couple spare frames and, not really have much to worry about. Just replace the frame when it appears worn out or shows cracking.


@Thad, I tried doing that with the M&P SHIELD 2.0 but can’t find any info on whether it was first released in 9mm or .40 caliber.
Perhaps you know a source or remember when it was first released?

Unfortunately I have very little knowledge about that specific series. What I can offer is that I have tried out my girlfriend’s 9mm Shield and, it is a dream to shoot. Hers is the Gen 1 but, if I hadn’t already developed a liking for my Walther I’d get that without hesitation.

If service life is a driving concern, I believe it shouldn’t be too hard to find that info. Then compair the 9 vs .40.

Compare the 9 vs the .40 in the sense of which caliber I feel is a better fit, correct?

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For sure. The training ammo is around 50% more expensive for a 45 than 9 mm. 40 is somewhere in between. In self defense ammo, it becomes a little different. Using Underwood as an example, 230 grain +p hollow points are 18.99 for 20 rounds. 124 grain +p 9mm are 15.99. Now, to fully load my carry gun and the spare magazine I came with, I need 17 rounds, 1 box and 3 rounds left over. To fully load a similar sized gun, like a Glock 19, I need 31 rounds. 2 boxes. This leads to the next point, in 2 identical sized guns, the M&P 45C(1.0) and the Glock 19 I have 8+1 rounds of 45 vs. 15+1 rounds of 9mm. Same size, even use the same holsters. Last is the shoot ability. I rank it high on my carry gun list. Some very popular carry guns, may not be the best for some shooters. Like me. I’m 6’1”, 260 lbs, so a little bigger than average. I can’t hit the broad side of a barn with guns like a Ruger LC9. I can shoot my .45C all day, accurately. The LC9, or a Glock 43, or something similar would be a lot easier to carry, but useless in my paws. The smallest gun I can shoot accurately is a Shield. Shield are only marginally smaller than my 45, and I don’t really gain capacity for the trade off, so it’s a double stack of “Short, fat, and slow” for me. :grin:

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That, plus if you are worried about the service life of each. I believe S&W publishes that information.

The .40 will have more recoil than the 9.

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I knew that the .40 would have more recoil than the 9 but I figured it wouldn’t be that much more. Looks like I have some research to do then.

For example, I have a Walther P99as full size in .40 S&W and, a compact P99as in 9mm and, from my perception both recoil amlost exactly the same

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The better gun is the one that you shoot the best with and are comfortable with.

I dont have a .40. I have several a couple 9mm. Couple .38spl, 1 .45, and of all of them, my 9mm is carried the most.

While more awkward in my hand. My P95 I can shoot more accurately than any of my guns.

My regular carry these days is my G2C, I’m good enough with it to be comfortable carrying and depend on it. Fits my hand well.

In the debate of .40 or 9mm, dont let the caliber be the deciding factor, let what fits best be the deciding factor.


I had been out of the firearms community for a couple decades before recently making my way back in. I was intent on getting a .40, that in between caliber as was mentioned. People who know a lot more than the majority of gun owners told me I was hung up on the 9mm caliber of many years ago, and that with the advancements that have been made, they all suggested, and carry 9’s. You could read until your head spins (I did) and still come out scratching your head. We’re dealing with handgun calibers; unless it’s a shot to the central nervous system, there is no “one stop shot”. Look up ballistics reports (Lucky Gunner has some good ones), expert reports that the differences between 9, .40 and .45 aren’t that much to make a difference, real life shooting situations, etc. The most important thing is how well you can carry and fire the weapon, how fast you can get back on target between shots, and of course, shot placement.

After doing my homework, I went with a 9mm and don’t regret it.


I originally went with 9mm because of capacity. I never thought about any other caliber.

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That’s another good point. I fired .45s in the Army and owned a .357 Magnum. At that time, the 9mm was considered underpowered and it was shortly after the FBI Miami shootout which actually resulted in advent of the .40 S&W caliber. Well, obviously things have come full circle and there have been advances in ballistics. And if you want to add a little more punch, distance and accuracy to your home defense situation you don’t even have to change calibers; you can add a pistol caliber carbine.

Hm. I haven’t thought much about a PCC gun at the moment. But that’s not a bad idea. You don’t have to worry about the over-penetration like you might in a 5.56 or 7.62 if you were to use those for home defense.

Yes, definitely a thought. Of course it all depends on the layout and size of your home/dwelling. 5.56 and 7.62 could definitely over penetrate, and most likely wouldn’t be appropriate for inside. Shotguns would be better suited for interior defense, with the right load. I like the idea of not having various calibers of ammunition, and if you’re into the possibility of the SHTF, the pistol caliber carbine could fit the bill while only having to carry one caliber. And the KelTec Sub 2000 uses magazines from S&W, SIG, Beretta and Glock, so if you have one of those particular handguns with the specific model, you don’t have to carry different magazines.


My carry is either a Glock 23 .40SW or Glock 26 9mm

My first pistol was a Sig 9mm and I loved it, should have never of sold it.

As far as .40SW I’ve been a fan of the it ever since I rented then purchased a Glock 22. My friend who was my Obi Wan laughed at me stating why would I waste my money on a fad chamber that will trend out? After he was hogging my pistol when we went to the range he went out and bought a USP in .40SW.

Fast forward to today I have a .45ACP Glock 21sf my wife loved it so much and pretty hogged it as well I went and bought a 2nd Glock 21 standard frame with night sights.

Before that she was considering to get a Glock 19, she actually preferred the Glock 22.

I say try it out, if you like it, can be consistent and the price is right then go for it.

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Love the variety of gun preferences here - and all for great reasons!

@KenM - Does your wife carry the Glock 22?