State Your Case: A Fair Comparison of 9mm vs. .40 Smith & Wesson

Today on State Your Case we’re taking a look at two of the most hotly debated and widely carried cartridges of our day and putting them head-to-head: the 9mm and .40 S&W. The only thing I ask is that when you state your case about what I write here, at least try to be composed. Here we go.

The 9mm (9x19mm Luger, NATO, etc.) is probably the most common centerfire pistol round on the market today. There is no denying that fact, like it or not. To balance this article properly, we will start by looking at some points that make the 9mm less desirable than the competition. Firstly, the 9mm isn’t widely known for its power. When I talk to owners of the .40, I hear that they went with it over the 9mm because they says it isn’t powerful enough for general carry and duty use. This is both true and untrue.

The standard 9mm, when loaded with anything in the 115gr-147gr FMJ style, isn’t a great performer. It penetrates well, but due to low frontal area and a ‘pointy’ bullet profile, it tends to lack in tissue damage and ‘stopping power’. Yes, stopping power is a made-up buzzword, but it’s thrown around a lot when talking about smaller vs. bigger calibers. In terms of simple physics, the .40 has more kinetic energy due to higher projectile mass given equal velocity. Higher energy and a wider, flatter bullet make the .40 objectively better than 9mm FMJ in most circumstances.

When it comes to hollowpoints and other modern expanding bullets, the .40 still has an advantage again over 9mm. Because of the greater bullet mass and thus lead on target, the .40 can expand more and deliver more devastating wound channels. The 9mm has a deficiency here as it can only expand so much, and in many cases the small bullets don’t have enough physical material in them to open up very wide. These, again, are generalizations, but they do hold true for most available products.

The .40 S&W has its greatest advantage in that it is substantially more powerful than 9mm in most handguns. But the power level is where things tend to go fuzzy for many .40 owners. That greater energy results in greater recoil, which has given .40 a reputation for being “snappy.”

For quite some time, the commercial .40 S&W options were about equal to its parent round, 10mm Auto. That gap has widened in recent years as many companies are now loading 10mm Auto to its full-house potential. The .40 can be thought of as 10mm -P in most ways.

The 9mm has gained in popularity because it offers several things that make it something of a Goldilocks cartridge. Smaller, lighter guns can be had and they aren’t brutal to fire. Most standard-sized pistols in 9mm can hold 15+1 or 17+1 rounds, which is a significant advantage in combat and competition. The 9mm is also inexpensive in bulk when compared to other centerfire rounds. It’s easy for almost any shooter to use and readily available virtually anywhere.

As far as the performance of the cartridge is concerned, the 9mm has benefitted from modern materials and engineering more than most any other pistol round. The commonality of 9mm means that the market has seen an explosion of innovation. Modern 9mm self-defense ammo is incredibly good compared to decades past and can sometimes outperform larger calibers in barrier penetration and ballistic tests. But there are limits there.

As far as guns go, the 9mm and .40 S&W are often chambered in models that have identical or near-identical frames like the GLOCK 17 and 22, Smith & Wesson M&P SHIELD 9 and .40 series, and many others. Side-by-side, .40 caliber pistols are lighter than 9mm guns, but only marginally. Recoil is more noticeable and capacity is slightly less with .40 as opposed to 9mm.

The argument that the 9mm is better solely on the merit of greater magazine capacity is only marginally true, as it’s usually a difference of only two rounds given the same exterior magazine dimensions. For many people, the extra two rounds are a worthy sacrifice when the greater bullet mass is considered.

Along the same lines, the 9mm has an advantage because it can hold more ammo for less weight than the .40 S&W. A magazine load of 17 rounds of standard 124gr 9mm adds about 7.5oz to the gun, where an identically sized 15 round mag loaded with standard 180gr .40 S&W contains about 8.25oz of ammo. This means that, given the same physical size for a 3-mag loadout, the .40 adds 2.25oz and loses six rounds. The heaviest 9mm loads are virtually all lighter than the lightest .40 rounds, so the weight consideration is valid, but not a huge deal.

At the end of the day, the .40 S&W is something of a fading star. The general population has been gravitating towards 9mm over the last couple decades and the .40 is losing significant ground in most markets. Just check your local gun store’s used gun counter for evidence of that.

While the variances may not be very significant when looked at on paper, fewer real-life end users are going for the .40. Substantial technological improvements in 9mm ammo design have resulted in widespread adoption in both law enforcement and civilian circles.

The difference in recoil, capacity, and ease of use may be minute to many, but the long-term edge goes to the 9mm. If I had to assign a winner here, it would have to be the 9mm. I don’t say that lightly, as I believe that the .40 is a very good cartridge considering the circumstances around its design and characteristics.

In an identically sized gun, the 9mm just has more going for it. If I were to go for a large handgun, I would probably look at 10mm Auto as opposed to .40 S&W because it does everything the .40 does, but does it better and with only a marginal increase in weight.

As objective as I tried to be in this piece, I just can’t give the .40 the title. As a stand-alone, .40 can run with the best, but it just can’t quite get into that sweet spot that the 9mm has claimed. I believe that the .40 has a place today, but I’m just not sure where that place is when 10mm, 9mm, and .45 ACP are dominating the automatic pistol market.

comments

  1. avatar AZgunner says:

    My department just announced that we’re phasing out the G22 and will be replacing them with Gen 5 G17 pistols. Some officers are upset, but I’m somewhat indifferent. I don’t think the difference is large enough to be a significant issue and I won’t feel undergunned with a G17 and good duty ammo. I already carry 9mm off duty.

    1. avatar Sgt Bill says:

      I carried a G22 .40 as a LEO for many years and never felt under gunned. Real life police shootings with .40 had good results. However, I now carry a G43 9MM most of the time because of concealed comfort and lighter weight. As the military has to carry FMJ rounds I was surprised that they didn’t move to the .40 years ago since it is a bigger bullet and flat nosed.

      1. avatar Bearpaw says:

        A fair comparison is found in the pawn shops. Piles of .40s. Zero 10s, and an occasional 9.

        .40s just aren’t the cool kids anymore. Not that they ever were.

        1. avatar Jon in CO says:

          I’m a weekly frequenter of pawn shops. Never know what some idiot is going to dump off because he didn’t budget correctly. My local ones have an entire case of 40’s, most of the 9’s are brand new guns, and I’ve seen zero 10mm in there ever. (Still holding out, I want a Gen4 G20) A few 45’s here and there, mostly 1911’s. Tons of AR’s and bolt guns people bought for hunting season and decided not keep.

        2. avatar anonymoose says:

          Unless you gangsta. Gotta have dat Glawk Deuce-Deuce, knowwhatimsayin?

        3. avatar Beardo says:

          No. I don’t. And if you’re trying to be funny, you failed. Miserably.

        4. avatar Ed says:

          Used 40’s are way cool when you get them dirt cheap and put a .357sig barrel in them.

    2. avatar California Richard says:

      After 30 years of data collection, NIJ said there is no qualitative difference between .40 and 9mm when it comes to killing 2 legged critters. They found that shot placement was the critical factor when it came to man-stopping. That’s why FBI, and by extension your department and soon all departments, are going back to 9mm.

      You say you never felt outgunned with .40? NIJ statistics don’t care about your feelings….. 6.5 Creedmore cares though.

      1. avatar kevin says:

        LEO’s have to train lots and lots of different sized people, many who start off with little or no skill. It’s easier to train people with a lighter round. People who can’t shoot well are probably better off with a 9mm for that reason alone. Plus there’s value to having everyone shooting the same round out of the same style gun. It’s a valid decision with solid logic behind it, but that doesn’t mean that 9mm is superior, just that equipping a department with it is a logical compromise.

        1. avatar California Richard says:

          9mm superior? Absolutely not. Equally effective? According to the 100,000 NIJ case studies: absolutely. Plus it has all the added benefits already addressed by other people here to include yourself.

          .40 S&W is itself is a compromise. It started life as a neutered 10mm round that mathemagicians said was theoretically better than a 9mm. 30 years of experience has shown the theory to be false.

    3. avatar kevin says:

      Ah, but how about a state where you’re limited 10 round magazines- do you want 10+1 of 9mm or 10+1 of .40 in the same size package?

      1. avatar Marty says:

        No, I’d want to move out of that state.

        1. avatar kevin says:

          I like CA and I’m not going anywhere, any time soon.

          I’ll take 10+1 of .40 over 10+1 of 9mm any day of the week. In fact, I’ll take 13+1 of .40 over 15+1 of 9mm.

          And practice. The recoil just isn’t that bad and there’s extra power there. I understand fast follow up shots, but if you’re not equipping an entire police force and don’t have to manage training the recoil-averse, .40 seems to be the way to go.

        2. avatar Marty says:

          Yup, I liked Kalifornia too, until the Socialists showed up. Born and raised there, retired there. They outlawed a lot of the firearms I owned. One month after retirement, I was a resident of a pro gun state, with 10 times better hunting and fishing, although I must admit, I do miss the deep sea fishing. But, Kalifornia is not done with their anti gun laws. More to come next year. Was back there two weeks ago after 5 years. What a total shock. San Diego has become a trash filled city. Illegal alien camps along I-5 for as far as the eye can see. Glad I went though. My wife was always talking about how much she loved San Diego. After seeing it this time, she says she will never talk about it again. Remember, Kalifornia will not be content until they remove all firearms from civilian ownership.

      2. avatar California Richard says:

        To California’s credit, the powers-that-be de-felonized 10+round magazines. Now its an infraction like having a BBQ on a spare-the-air day or driving while wearing flip-flop sandals. There’s still this lingering misconception that you’ll go to prison and Californians handle their magazines like its a kilo of cocaine.

    4. avatar Tile Floor says:

      Our Dept. is doing the same thing in January. I think its a smart move. We’re also switching to utility uniforms with external vest carriers, much more comfy than being bundled up like a tick about to pop

  2. avatar Kap says:

    bigger bullet make bigger holes.

    1. avatar JasonM says:

      So a 230gr .452″ bullet in a .45 ACP round makes a bigger hole than a 175gr .308″ bullet from a .308 Win cartridge?

      You’re missing a very important factor in making big holes (ke = (mv^2)/2).

  3. avatar Jay in Florida says:

    Bigger is still better overall. The major difference to most is in recoil. Which to me is marginal. Capacity. Equal sized guns can carry more rounds then I should ever need. That all said I myself do carry a Commander size 1911 in 10mm with full power loads. 1 spare mag. If more are needed. I’m in some deep doo doo.

    1. avatar Gman says:

      And yet the .22LR reigns supreme as the weapon of choice to kill humans.

      1. avatar jwm says:

        I suspect that’s cause the .22 is just by far the most sold gun/round out there. There were a couple of times in my youth when I couldn’t afford anything other than a .22. So that’s what I used.

        1. avatar Gman says:

          Whenever I travel away from home I always put my 10/22TD in the trunk. It’s my go to trunk gun. 4 BX-25’s, a handful of 10’s, a full cleaning kit, and about 2500 rounds of ammo. The Nikon .22BDC scope is dialed in perfectly for 100 yards. The way I look at it if I have to hunt I can. If I have to fight my way home, being able to reach out to 100 yards with a 3-9 scope and 2500 rounds is a very nice capability. If I’m away for an extended trip I’ll drop the S&W M&P22C in the case as well.

        2. avatar jwm says:

          In a survival scenario I would much rather have a decent .22 rifle as just about anything else. I could talk myself into a stack barrel. .22 on top and .410 or 20 under.

          But my .22 rifles would do me just fine.

      2. avatar Marty says:

        Killing is not the goal. Stopping is the true goal. Yup, .22’s can and do kill, but what does the bad guy do before he dies.Yea, I’ve seen a .22 kill immediately, but that’s not the norm. Yes, if the bullet hits the rib cage, and bounces from rib to rib, It can be devastating, but again not the norm.

        In my case, due to medical issues, I’ve gone from the heavy Sig 220 and the Colt 1911 in 45 acp, to the S&W M&P Shield 9mm. The gun empty is 18 oz and it shoots like a dream. It’s so light and compact, I sometimes forget it’s there. Getting old is a bitch,I’m just glad the manufacture’s continue to come up with quality weapons us older folks can comfortably carry and accurately shoot.

      3. avatar anonymoose says:

        I always heard that 9×19 was the most common caliber worldwide, but that you are most likely to be shot with a .380 because that’s what muggers prefer in the last few decades.

      4. avatar jwtaylor says:

        Complete myth.

  4. avatar raptor jesus says:

    Modern wound science shows that the only thing that matters for PISTOLS is penetration, followed by expansion. We’re basically poking holes in flesh. Secondary wounding effects from rifle rounds don’t occur at pistol velocities.

    Kinetic energy is meaningless in this framework assuming a round has sufficient penetration. Kinetic energy is also a detriment if the round over-penetrates and doesn’t dump that energy into the intended target.

    Lucky Gunner has done a lot of research showing that 9mm performs as well (or better) than .40, with the added benefit of more capacity (or less weight for equal capacity), less recoil (easier to shoot, easier on guns), and its cheaper.

    https://www.luckygunner.com/labs/self-defense-ammo-ballistic-tests/

    1. avatar 3days2never says:

      I don’t know why people keep repeating this horse sh*t, its not true. You can get rifle stopping power in a handgun round, the problem is all the internet commandos are testing the wrong rounds. A .357 sig underwood round from a 4 inch barrel can reach 700lbs of force. You want me to believe this is equal to a 300lb “hole poking” 9mm.

      You take a .357 sig Dynamic research technology round and it replicates the ballistics of getting
      hit with a 556 rifle. I know because I’ve seen it on deer.

      Seriously? You guys need to stop drinking the koolaid and learn to think for your selves.
      You’re all becoming these zombie lemmings thats are just repeating things over and over again. Repetition is actually a form of mind control, if you say something enough times people believe it even though its not true. Seriously, wake the F up. Repeating something a thousand times
      doesn’t make it right.

      There is an old saying, its if the “masses” are doing something, then its probably the wrong thing.
      You guys need to stop repeating and use your heads.

      1. avatar raptor jesus says:

        You clearly didn’t bother to click on the link and see the actual performance of the actual bullets in actual testing.

      2. avatar Thunder Chunky says:

        Geez my man, go get laid or something.

  5. avatar Kountryboy says:

    I’m afraid the .40 S&W is going to become the 16-gauge of the pistol world. It will still have it’s followers, but it will never regain it’s heyday.

  6. avatar Gman says:

    I carry a 9. I am more confident with my shot placement and speed with 9 than I am with .40. Perhaps that is a lack of practice with the .40. I really don’t think there is such a large difference, ballistically speaking, to lean one way or the other, so to me it is simply a matter of preference. My wife carries a .40.

    1. avatar Thunder Chunky says:

      I bet your wife makes all the financial decisions, works on the cars and mows the lawn, too.

  7. avatar Timothy says:

    Most DGUs are resolved without a shot fired. Most DGUs where a shot is fired are resolved when the bad guy doesn’t want to get shot again and gives up. Of the very few DGUs where the bad guy keeps coming after getting shot, the bigger round makes bigger holes and the smaller round allows faster follow up holes.

    Pick what you will carry, what you will practice with, and what you trust. If that’s a 380 or a revolver in 500 S&W or anything in between, then you will be just fine.

  8. avatar Stick and Rudder says:

    I never really got the caliber war between 9, 40 and 45. As a civilian ccw holder my primary goal is to break contact with a physical threat and pretty much all handgun calibers will accomplish that goal. Situational awareness and shot placement are way more important than caliber…..

  9. avatar TommyG says:

    Guy I know who trains our local SWAT team told me the competition is over and the 9mm wins. Its a effective human killer will less recoil, more capacity, and less cost. Me I’m old fashioned. 45acp is still my choice for carry and target.

    1. avatar New Continental Army says:

      Despite what the fan bois say, 9mm didn’t “win the caliber war.” 9mm did win the conceal carry war, though. For obvious reasons.

      1. avatar jwm says:

        I think it’s safe to say that the 9×19 is the most made and sold handgun round world wide, US included. With the added win of being the most used sub gun round world wide.

        There was no caliber war. It was a massacre and the 9×19 did it.

      2. avatar balais says:

        9mm won the war over 60 years ago, i dont know what you’re talking about

      3. avatar MikeINpa says:

        Like the cold war with the russians….9mm just had to out spend them….more technology…more production capacity….produced a cheaper better bullet.

  10. avatar Ing says:

    To me, the .40 is the worst of both worlds. You have lower mag capacity than 9mm, lower power/smaller holes than a .45, and snappy recoil into the bargain.

    The choice is between 9mm or .45, and I go with the 9mm because of higher mag capacity, lower recoil, and virtually identical fight-stopping performance with modern defensive bullet design. And just as important as any of that is the much lower price for ammunition, which means I can afford to practice more.

    All that being said, there’s really no wrong choice — as long as it goes bang when you need it to and you know how to hit the target, you’re good to go.

    1. avatar Steve says:

      The .40 and the .45 are about equal powerwise.

      Federal HST ammo. the 180 gr .40 @ 1010 fps = 410 ft-lbs
      Federal HST ammo. the 230 gr .45 @ 890 fps = 405 ft-lbs.

      If you want to go really hot, the hottest Buffalo Bore loads

      155gr .40 @ 1300 fps = 582 ft-lbs
      185gr .45 @ 1150 fps = 543 ft-lbs

      As for bigger holes, if you use the right bullet there isn’t much of a difference either. Federals 180 gr .40 HST load expands to 0.95 in gelatin. The 230 gr .45 HST load expands to 0.93.

      In alot of ways the .40 and the .45 are ballistic twins.

      1. avatar Bob h says:

        40 and 45 +p are almost the same, standard 45 and 9mm +p are less powerful than 40 significantly. What you would call the worst of both worlds others see as a boon. You can have a round more powerful than 45acp that comes in the same lightweight guns with almost as high capacity as 9mm. I definitely see why 40 happened. I think the 10mm revolution is probably as equally responsible for killing 40 as the advancements in bullet technology. With all these choices I still carry 357 Magnum and 45LC most often EDC, although I’m looking at a 40 snub nosed revolver for my lightweight summer shorts and T shirt load out. To each their own!

        1. avatar Bob h says:

          Forgot to say why a 40 snubby. More powerful than 357 Magnum out of a 2″ barrel due to case length and 40 being optimized from the start for a 3.5″ barrel, and 40 is A LOT quieter than 357 especially from a short barrel.

        2. avatar Steve says:

          My left ear has been ringing continually since 1996 when I shot a .357 magnum once without hearing protection. ONCE!

          I love me some .357 mag, but damn it is hard on the ears.

        3. avatar Bill Cuthbertson says:

          Steve I did the same thing back in the eighties and have had the ringing and deadness in both ears for not wearing ear protection. But back then it wasn’t even talked about like it is today.

      2. avatar Tex300BLK says:

        9mm Speer Gold Dot 124gr +P: 1220 fps/ 410fpe

        forty what?

        1. avatar Bob h says:

          40 S&W Speer Gold Dot 155 grain JHP 1200 fps /496 fpe.

          Underwood loads 165 grain Gold Dots at 1220 fps. If your point is that 9mm is just as powerful, it’s not. Nobody should argue that point. 40 has bigger heavier bullets traveling at the same speed with almost the same capacity.

        2. avatar Tex300BLK says:

          It was a direct reply to Steve above where he listed two common SD loads for the 40 (180gr HST) and 45 (230gr HST) which came in at 410 and 405 fpe respectively.

          The bigger issue with your comment is that the 86 fpe difference* (almost half the energy of a 22lr) means nothing outside of bench racing/caliber war pissing matches.

          Are they equal? No. Are they meaningfully different in real world self defense scenarios? Not hardly, and there’s plenty of testing that backs this up (see the lucky gunner article someone linked elsewhere in the comments for just one example).

    2. avatar Ardent says:

      I carried .40s for years, figuring they split the difference: capacity more like a 9, power more like a .45, in other words, the BEST of all possible worlds, and frankly if I could buy .40 for closer to the cost of 9, that’s what I would still shoot and carry. These days my usual EDC primary is a G19. Not because 40 sucks, but because I want to carry what a practice with, and 9 is far cheaper to shoot.

    3. avatar Nelson says:

      No Just have weak hands admit it.

      1. avatar Ing says:

        Ha! Okay.

        I actually would’ve bought a .40 for my first handgun, but the wife has a weak grip, and she had issues racking the slide. Since it needed to be a gun we could both handle, I ended up with a 9mm.

        Since then, having shot various guns in 9mm, .40 and .45, I’ve decided that what I once thought was a ballistic sweet spot, best of both worlds round is actually the worst of both. In the modern world, 9mm wins, no contest.

        If I had bought a .40, would I be singing its praises now instead? I dunno. Maybe. Circumstances and randomness have a far larger role in these opinions than we like to admit.

  11. avatar Geoff "Mess with the bull, get the horns" PR says:

    The Glock 23 in .40 S&W fits my hand like a glove.

    Is there any reason why I cannot just drop a 9mm barrel in there and get the same hand-fit I like?

    1. avatar Rob says:

      No reason at all.
      A real power move would be to drop a .357 Sig barrel in. You can even use the same mags.

    2. avatar UsedToBePun says:

      It is doable. Sometimes you have to also use a different spring or it can be finicky. There are (or were) youtube videos out there detailing the process. Maybe on Full30 now…

      Lone Wolf and others sell the conversion barrels.

    3. avatar uncommon_sense says:

      Geoff PR,

      If you like the grip of the Glock 23 and want to shoot 9mm Luger, why not simply purchase a Glock 19 which should have the exact same grip and frame (if I am not mistaken)?

      In terms of converting your Glock 23 to 9mm Luger, keep in mind that your bolt face and extractors are sized for .40 S&W cartridge bases. That means they are slightly oversized for 9mm Luger cartridges. The crazy part: I hear that it works reliably anyway.

      I would not personally carry a Glock 23 with a 9mm barrel (and even a lower-weight recoil spring) for my daily-carry self-defense handgun for fear that it would not be reliable. Perhaps it is anyway even though the extractors are sized for .40 S&W.

    4. avatar CZ Rider says:

      A 9mm conversion barrel will work fine. Might be good to check the recoil spring weight, .40 might have a heavier enough spring to cause issues. You can also slap an entire G19 slide on the 23 frame if you’re so inclined. I have a complete .40 slide for my G26, works great. All I need is for someone to shoehorn a .45 conversion into it and I’ll have the big three covered on a single frame. Take that, p320!

      1. avatar anonymoose says:

        I do believe all Glocks come from the factory with 16 pound recoil springs, regardless of size or caliber.

      2. avatar Cymond says:

        You’ll never get a 45 ACP into a 9mm/40S&W magwell, because the 45 ACP is longer that the magazine, but check out the G37, G38, and G39 in a cartridge called 45 GAP. It was specifically created to give 45 ballistics in a 9mm sized gun.

        The downside is that it was a complete failure of a cartridge that makes 357 Sig look common.

    5. avatar Just Sayin says:

      G23 w/ factory barrel, Lone Wolf .40 threaded, Lone Wolf .9mm threaded, Lone Wolf .357sig threaded.
      I use the same factory g23 .40 mags for all calibers. No issues.
      I use the same recoil spring for all calibers. No issues after 500 round break in.
      Covers the bases for me.
      G20 + .45 threaded barrel is on the list.
      THAT will cover all my bases, 9, 10, .40, .357, .45

    6. avatar Jon in CO says:

      Theoretically, yes you can. If you want 100% reliability, pick up a 9mm extractor, and a 9mm trigger housing (it holds the ejector). Minus the barrel, all of those parts should cost about $25. You can swap all of it out in about 3 min.

    7. avatar Scoutino says:

      Geoff, if GLOCK fits your hand like a glove, you must have hands like an industrial robot. Those things have corners on their grip for Pete’s sake! Now CZ75 or Walther PPQ have grips made for human hand. But if it works for you…

  12. avatar Tom says:

    I have a G27 and have considered installing a .357sig barrel. I hear a lot of speculation on ” over penetration from .357sig. Any comments about that?

    1. avatar MikeINpa says:

      More penetration means you just need to find a bullet that expands quicker to dump that energy into the target. I put a lone wolf barrel in mine, its great.

  13. avatar jwm says:

    Space filler post. Caliber wars are for bored folks with nothing better to do.

    1. avatar yitz says:

      yet…he you are 🙂

      1. avatar jwm says:

        I’m supporting my favorite gun blog……….. and I’m bored.

        1. avatar pieslapper says:

          If only they would bring back the caption contest.

  14. avatar Steve says:

    The recoil difference between 9mm and .40 really depends on the gun you shoot them in. I have a M92 Beretta and a M96 Beretta. Same gun, just one is in 9 and the other in .40. In a full sized steel gun like the Beretta there is basically no recoil difference between the 9 and the .40. IMO, in full sized guns the 9mm loses its biggest advantage because the recoil difference is negligible.

    In compact and subcompact guns there is a noticeable difference. I will grant that.

    One advantage the .40 has over both the 9mm and the .45 is sectional density which makes it superior at penetrating degradable cover like windshields and car doors. Federals HST testing showed that a 180 gr .40 HST will go through a windshield, penetrate 11.5 inches into ballistic gel and still expand to 0.73. The 9mm on the other hand only penetrated 10 inches and only expanded to 0.52. I can’t remember how the 45 did off the top of my head, but I do know the .40 outperformed the 45 too.

    Thats why, other than for budgetary reasons, I think police are making a mistake switching from the .40. Cops are far more likely to engage someone behind cover, especially windshields and car doors, and the .40 is markedly better at defeating those types of cover.

    1. avatar uncommon_sense says:

      Hah! Steve and I said basically the same thing!

    2. avatar Morelia1976 says:

      The gun you use does make a difference. I believe .40SW’s biggest challenge is that most pistol manufacturers don’t make true .40SW pistols. Most people here are talking Glocks where there is only a 5 to 10 gram difference between a G19 and a G23 depending on which generation it is, and at most a 20g difference between a G17 and a G22. There is a 67g difference between a VP9 and a VP40, and a 50g difference between USPs chambered in 9mm and .40SW. For some reason there is no difference in P2000s, but everyone that shot my P2000 in .40SW stated the recoil was very manageable, including my 13 year old nephew, so maybe HK designed it for .40SW from the start. Glock simply doesn’t make .40SW pistols, they make 9mm pistols rechambered in .40SW, and that’s why they’re ‘snappy’. The best shooting .40SW I’ve laid hands on was a Sig P229 Elite, virtually no recoil because it was designed to mitigate the extra energy.

  15. avatar uncommon_sense says:

    I personally chose .40 S&W over 9mm Luger for two reasons:
    (1) Slightly larger bullet diameter which means slightly greater probability that a hit will incapacitate my attacker faster.
    (2) Superior barrier penetration such as a car windshield at an oblique angle or a solid wood barrier.

    My 180 grain bullets will sail through a windshield without deviating from their original trajectory even at very oblique (shallow) angles. The same is definitely NOT true of popular 9mm Luger 115 grain and 124 grain loads. And my 180 grain bullets easily punch through 3 inches of solid wood. I doubt that popular 9mm Luger 115 grain and 124 grain loads will do that.

    Having said all that, I believe that the choice for 9mm versus .40 S&W, at least from a terminal ballistics perspective, is whether or not you will carry a compact or full-size handgun. If you are going to carry a light-weight compact handgun, I give the nod to 9mm Luger because most people will want its lesser recoil in that light handgun. (In that case lesser recoil translates to better marksmanship.) If you are going to carry a full-size handgun, I give the nod to .40 S&W because felt recoil will be about the same as the recoil of 9mm Luger in a light-weight handgun. (And that should mean the same level of marksmanship.)

    If cost is your primary concern, then 9mm Luger obviously wins since plinking ammunition is definitely less expensive than .40 S&W. (Premium self-defense ammunition is about the same cost no matter what caliber you purchase.)

    1. avatar Tex300BLK says:

      “I doubt that popular 9mm Luger 115 grain and 124 grain loads will do that.”

      I doubt that anyone not engaged in a pissing match defending their caliber of choice cares either.

  16. avatar Qwerty says:

    In my completely subjective testing of 40 and 9mm, yes, the 40 made bigger holes, but recoil in a Glock 23 made followup shots slower.
    My Glock 19 makes smaller holes, but it also makes more of them which, I think, at least partially negates the advantage of bigger/fewer holes.

  17. avatar Darkman says:

    Shot placement negates the entire argument. A properly placed shot ends the confrontation regardless of size. So Practice…Practice…Practice.

  18. avatar GS650G says:

    I have the walther PPQ in .22, 9mm and .45
    I think I’ll look for a cheap used PPQ in .40 just to round out the collection

  19. avatar TommyJay says:

    If you are very experienced and have a nice gun collection, then you don’t need this article. If you are still learning like me, then focus on 9mm because you can buy and shoot thousands of rounds and not break the bank.

  20. avatar Anner says:

    I’m confused. Folks that discuss (much less write about) the merits of various defensive in this detail are well beyond the realization that meat on the dinner table didn’t miraculously arrive on the grocery shelf in a styrofoam tray:

    https://www.thetruthaboutguns.com/2018/10/jon-wayne-taylor/proof-in-the-pudding-wilson-combat-300-hamr-takes-a-bull-elk/

    Josh’s comments…I don’t know what’s going on.

  21. avatar Southerner says:

    Advantages for the 40S&W: If training ammunition, ie FMJ, must be put in primary use the fact that all .40 FMJ ammo has a flat nose is of great advantage.* And in those states of lesser freedom, many compact 40S&W chambered autoloaders have a standard magazine capacity of 10 rounds*. The recently released Bersa TPR40C is a prime example.

    *Especially in New Jersey: No HP ammo or over 10 round magazines!

    1. avatar Micah says:

      No HP ammo allowed?… shows how ignorant the people who make gun laws in New Jersey are.

  22. avatar S.Crock says:

    They all work. There are marginal differences in performance which are mostly just seen in internet gel tests. Arguing over a few rounds of capacity, a few cents of cost, or ~100 FPE is somewhat silly. Recoil is the most legitimate concern in my opinion. However, out of a G22 or a G17 I find that difference minimal.

  23. avatar Neil says:

    Newbies, take it from a grey hair:
    What matters is pick a gun you are comfortable with. If that is a 45ACP, why that is what you’ll practice with and be good (it was the caliber for me for many years ).
    40 S&W can be snappy in a light glock. Remember, joint pain is the derivative of acceleration (“jerk”) so a light gun will hurt more (like those Glocks). A USP in 40S&W and 9mm… well the USP tames the beast.
    But if you’re really going to practice, and I’m not talking about 2 or 3 boxes of ammo per year, but really practice where you are paying for the ammo, 9mm is the volume deal and there are so many good guns in the caliber.
    Worse comes to worse, put a dual battery flashlight on any gun and that will tame it. Good 9mm
    Personally, try the VP9/VP40/VP45, S&W 2.0s, Sigpro (my favorite, but I’m weird), even pricier sigs, Glock gen 4/5, just avoid small CCW guns for the first gun.

    I have to agree with the above post, the caliber wars have been so overdone… I’m bored with them.

  24. avatar GunnyGene says:

    Folks who are obsessive about big holes and penetration, might as well just ditch their handguns altogether and go with a 12 gage and Brenneke slugs. 😉 I recommend the Green Lightning for all around use. 🙂

  25. avatar ferret427 says:

    Meh. Common carry pistol cartridges are basically the same when it comes to lethality. The trade off between light bullet high velocity/heavy bullet low velocity really makes no big difference in a pistol cartridge.
    The energy differentials and projectile behaviors between such calibers play a very small part in the outcome of a shooting. When it comes to common carry caliber comparisons it is really splitting hairs and one off situational comparisons.
    Pick a weapon that makes sense for your application, get used to the way that firearm functions, shoot it to become proficient with it in the manner that you intend to use it and that’s it.

  26. avatar FlamencoD says:

    Are those two pictures showing a light 9mm copper bullet vs. a heavy .40 S&W bullet? To be fair, you should show the same manufacturer, and similar weights vs. diameter bullets.

    Compare 9mm+p or +p+ and the gap narrows and nearly equals when it comes to energy. Most 9mm +p has around 400 ft lbs of energy out of a 4″ barrel, and some +p+ loads approach or exceed 500 ft lbs. Buffalo Bore has a 9mm+p load that is 115 gr @ 1,300 fps, which is 431 ft lbs of energy. Buffalo bore also has a +p+ load that is 115 gr 1,400 fps which is 500 ft lbs. That’s not far from a .357 mag from a 3″ revolver barrel.

    My carry ammo is 9mm +p 115 grain @ 1,246 fps out of a 4″ barrel which is 396 ft lbs of energy. For my home defense (5″ Springfield XD mod 2), velocity is higher, and energy is around 435 ft lbs. Not too shabby. I don’t feel under-powered with that round.

    1. avatar Steve says:

      For reference sake, the hottest Buffalo Bore .40 load is a 155 gr @ 1300 fps and 582 ft-lbs.

  27. avatar MLee says:

    Too much emphasis on B.S. of little importance. It’s infinitely more important to practice and carry. If you can draw your weapon cleanly and quickly, fire and hit your target consistently, that’s far more important than worrying about 9mm vs .40
    I’m surprised I wasted more of my time reading more opinions on this subject. It’s no different than the striker vs hammer riddle. It all comes down to picking a weapon you like and shooting it. Practice drawing, get training, get good with your weapon and the rest of the tired worn out reruns of 9m vs .40 will be nothing more than inconsequential time wasters. Really, WHO CARES!!!!

  28. avatar bigdaddytexasguns says:

    All this is BS. The one thing 40S&W has over 9mm is barrier penetration like a car door or windshield.

    Once the bullet hits flesh it has been proven by forensic experts that the wounds are similar between 9mm – 40S&W – 357SIG and 45ACP. So many factors from what the person is wearing to the type of build, type of weapon and type of ammo used. Also the angle of the shooter to the person being shot. Does it hit something before the person being shot? The distance between the shooter and person being shot. On and on and on, so many factors.

    Shoot what you like and what you shoot best. Make sure your gun is reliable. Make sure your ammo is effective and practice.

  29. avatar Jon in CO says:

    I take 9mm because of capacity. You can say that 2-3 rounds won’t make a difference, but it’s 2-3 more rounds I have. Since I’m a Glock fanboy, the 9mm has bigger mags, much more aftermarket support, and everyone on earth somewhere has one.

  30. avatar Warlocc says:

    I live in a state that only allows 10 round magazines.

    So “magazine capacity” isn’t a factor in which ammo I choose. I only get 10 shots. Gotta make those 10 shots count, so I don’t use anything smaller than .40

  31. avatar Nelson says:

    I keep hearing the .40 is too snappy. yeah that’s probably because you have weak hands.

    1. avatar FreakinPeanuts says:

      THIS! I carry a Walther PPS M1 in .40 daily. Once you get used to it its not that big of a deal.

    2. avatar kahlil says:

      I feel ya. The whole “snappy” comments always irks me for some reason.

      The subject of guns, ammo, and the like are sort of similar to the topic of wines – aromas, notes, nuances, etc. A bunch of pretentious snobbery. The gun kicks and has recoil, can you handle it? Good. If not, get a gun or caliber that suits you. Most people throw around words like snappy but likely have little understanding, they just repeat what others are saying in an attempt to look more knowledgable. For my part in semi auto pistols I’ve shot .22, .380, 9mm, .40, .45, and .50 AE. My experience is that I prefer .40 over all the other calibers, and that is my carry caliber. I like shooting big bore overall (even in revolver and rifle) so I gravitate more to .40, .45, or higher. .380 and 9mm just didn’t do it for me. I do occasionally carry my Rhino 200DS in .357, the grip and low barrel really manages recoil nicely, even with wood grips. Not too bad on the hand and follow up shots.

  32. avatar possum says:

    I always hear this about the 9 mm,” well with bullet xyz it’s just as good as,,. ,,,,”. Well what about running bullet xyz in just as good as? Say what you want, I’ve shot to many critters with quite a few calibers and 9 is not on my list as a dependable stopper. I look at it like,” if small and fast is so great then how come the 7.62×25 isn’t a popular cartridge?,”,,( 110gr sp at 1540 is pretty impressive however) but it sure ain’t no .45

  33. avatar FreakinPeanuts says:

    My ccw is a Walther PPS in .40. I enjoy shooting both my 9’s and .40’s. But I also reload. Which means that I can load .40 from 155gr to 200gr. It’s kinda like having 3 guns in one. It can shoot like a 9 a 40 or a 45

  34. avatar Greg says:

    My local shop won’t take 40s in trade. As they just sit and collect dust. SMUs experimented with 40 Cal and found it brought nothing to the table over 9mm. The weapons couldn’t take the high round counts.

    .50 GI FTW!

  35. avatar Kountryboy says:

    I remember reading in the book “Survival Guns” by the late Mel Tappan that he recommended choosing what was most effective in its least effective form, in case you couldn’t get your suped-up round and had to use FMJ. That meant he recommended .45 acp over 9 mm for defensive use. I also remember reading awhile back a piece by someone who worked in a coroner’s office, but right now I can’t remember his name. He stated that the autopsies he performed on gun shot victims showed that the .380 and 9 mm rounds would tend to glance off bone and not follow the original path, whereas the .40 and .45 were not affected in the same way.

  36. avatar Craig in IA says:

    I carry a Glock 43 (9mm) EDC but also a Shield 40 when I’m doing my 5 1/2 mile run every day, Hornady Critical Defense in both. I feel safe with either and occasionally carry the Shield elsewhere. I still have a ton of 10 mm bullets to load so I won’t be dumping my Glock 23, the Shield or 10 mm Gold Cup Delta Elite any time soon. It is true that the used shops have tons of cop trade-ins, Cabela’s in Rogers, MN had a shelf full of slightly Glock 22s and seemed to want way too much for them.

    My first choise would be .45 ACP but I’ve tried carrying my Officer’s ACP and an old Detonics I have but I’m not all that large and both weigh me down. I like their trigger action better but I’ve learned to shoot the Glock-type.

    The first pic in the article, BTW is certainly apples to oranges, 9 mm appears to be Critical Defense, .40 is FMJ…

  37. avatar FuzzyBunny says:

    Interesting report from the Office of Medical History

    CHAPTER II
    Ballistic Characteristics of Wounding Agents

    PHYSICAL ASPECTS OF THE MISSILE CASUALTY

    Page 140

    From an analysis of these facts and the requirements for penetration of skin and bone, it can be readily appreciated that the .45 caliber bullet is of little value as a wound-producing agent except in the softer tissues and at near ranges. The bullet often fails either to penetrate or to fracture bone and practically never shatters bone in the manner common to the rifle bullet or fragment. The Japanese and German sidearms with muzzle velocities of approximately 1,100 f.p.s. were much more effective as antipersonnel weapons than the .45 caliber weapon.

    Of course, the carbine with its much higher muzzle velocity has largely replaced the .45 automatic pistol and is a more effective antipersonnel weapon than any of the sidearms.

  38. avatar raz-0 says:

    My $0.02 on ballistics between the two:

    The FBI built a test. The industry designs to the test. As a result if you buy quality defensive ammo, it generally performs to the specs of the test plus or minus some negligible difference.

    If you are going to discuss the viability of either for serious social situations, I think the only place you will have something legitimate to say is in the case of using the cheapest of plinking ammo from both, and that’s a very pot vs. kettle kind of discussion.

    That being said, as a user of both cartridges I did notice one thing over the years that is related to cartridge spec and has generated real world issues. That’s the size of the recess ahead of the case rim. When pitsol ammo was getting scarce and everyone was making as much 9mm as you could during one of the panics + large military ammo orders, you got a bunch of bad 9mm hitting the market. teh recess on the 9mm is pretty narrow by spec, and either tool wear or relaxed QC was letting stuff out that was a bit too narrow and was not working well in a lot of guns. mostly of newer design. Things like cz-75 pattern guns and 9mm 1911s had less issue. Things like glocks and M&Ps had more. But once again. Good SD ammo wasn’t having these problems.

    For 9mm, it’s cheap, it wins capacity wars, and it’s easy to shoot. I hate reloading it though, and I find it less versatile than .40. Small components, crimped brass all over the place, tapered brass (a plus and a minus) etc.

    .40 I can load from mouse fart to heavy hitter, and if I want to pay for it I can go to the folks doing blended powder loads and get stuff nearly at 10mm power levels. I used to be able to say I’d get no crimped cases, but there is some out there now.

    But even then in the end, there’s not enough difference to really declare a winner, and your shooting lifestyle is more likely to declare winner than inherent traits of the cartridges combined with objective reality.

  39. avatar Vlad Tepes says:

    A number of years ago in one of the back columns of Combat Handguns Magazine they carried a shocking article on three .40 S&W Handguns that all blew up using factory 180 grain loads. They were a very strongly designed Ruger and a Glock and an old fashioned style but new Browning High Power. The cause was traced to the full power 180 grain loads that when they suffered bullet set back going up the feed ramp it produced a detonation because there was not enough air space in the 40 S&W cartridge and the powder got compressed. The ammo companies then quietly scaled back the power of the 180 grain loads to help to eliminate this problem but the word got out and every one then switched to the lighter 165 grain loads.

    Many 40 S&W guns were originally designed for the 9mm and when they were reverse engineered the life span of the handguns was greatly diminished. More than one Police Department dropped the .40 for this very reason, just not enough service life.

    The .40 recoils more than the 9mm and many people just do not shoot it as well because of this.

    The .40 carries less capacity which again never sat well with the general public.

    The .40 costs more per box of ammo than the ubiquitous 9×19 and the 9×19 is available worldwide in every country.

    The 9×19 is still the world standard military pistol cartridge for over 100 years.

    The 9×19 does the job and I can attest to its lethality because of the number of animals I have shot with it. Jeff Coopers bad mouthing of it as an anemic cartridge proved he never shot any living thing with it ever.

  40. avatar KL says:

    I go with 9 mm . Why ? cheaper . If people like .40 or .45 or whatever as long as they can afford the rounds go for it . Most humans do not want to get shot regardless of the round . I would assume in most cases most humans would stop and or run away after being shot .

  41. avatar The Realist says:

    I keep reading that 9mm home defense ammo has gotten so much better that it puts it on par with .40 Smith and Wesson. What people always forget to mention is that .40 ammo has gotten so much better. For example, what Federal or Hornady make in 9mm is also made in .40. The .40 has kept its edge.

  42. avatar Bill Craig says:

    You don’t mention the differences in sectional density, which relates directly to one of the ONLY TWO THINGS THAT REALLY MATTER in stopping a threat with a handgun – shot placement and penetration depth. Sectional density affects penetration depth.
    If you compare the 230g .45ACP, the 180g .40S&W, and the 147g 9mm Parabellum, you will find that the 9mm has the highest sectional density. The SD’s of the .40 and the .45 are essentially the same and the 9mm SD is 3.7% higher than the other two. This the reason that 9mm consistently out penetrates the other two in side-by-side tests.

    1. avatar Scoutino says:

      Why should we compare 147 gr 9mm to 180 gr .40? Why not 115gr 9mm to 165 gr .40? Or if you want to go heavy, 147 gr 9mm to 200 gr .40.

  43. avatar Scoutino says:

    Must…not…get..sucked…in..a..caliber…war!
    Okay, I give up, for last time, I promise.

    I like the .40 and in direct opposition to some previous posters, I see it as best of both worlds. Faster and better penetration plus larger capacity than .45 acp and heavier, bigger bullet than 9mm.

    From a full size gun the recoil is very manageable, even my 9 years old son can deal with it. Cost difference is negligible for me, since I cast bullets and reload my own ammo.

    I bought a 9mm conversion for my Witness, but use it mostly for new shooters, after they feel they want to move up from .22. To me the 9mm seems a bit anemic. Full house .44 magnum will get your blood flow faster.
    For concealed carry the 9 makes lots of sense especially from very small pistols. To each his own.

  44. avatar Darry Hartsock says:

    the .40 will always hit harder and make a bigger hole. No argument can challenge this. It boils down to one issue, can you handle and control the increased recoil and muzzle jump pf the .40?? Ammo prices are no longer significantly different.

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