9mm vs .40 S&W

9mm vs 40 cal

9mm vs 40

Usually, when people talk about what ’s the best caliber, it mostly has to do with concealed carry. The question that is constantly asked is, “What should I carry?”

You can check out our Blog on "The Best Way To Choose Your Next Concealed Carry Handgun"


Well, in order to come to a conclusion, let’s get to know these 2 calibers a little bit better. 


The 9mm has been around for well over a decade now. It was developed by designer Georg Luger, in 1902. Many people think that the 9mm Parabellum was an answer to the less powerful .380 caliber. This is false since the .380 didn’t come around for another six years or so. Check out our blog .380 vs. 9mm for more info on this.


The .40 S&W was developed by Smith & Wesson and Winchester for Law Enforcement as an answer to the Miami Shootout and the Federal Bureau Of Investigations ( FBI ) 10mm round. Law enforcement agencies and police departments wanted a round with equal performance in a smaller or medium frame gun. The round came out in 1990 along with the S&W Model 4006



Now, let us compare these 2 sought after rounds side by side. 9mm ammunition has a higher velocity due to the size of the round which is between 115 and 147 grain but not by much. Some data shows that they are almost identical. The .40 S&W will have a heavier projectile within the range of about 135 to 180 grain allowing this round to releasing more energy upon impact.  When it comes to ballistics the win goes to the 40 S&W


Here is where it gets interesting. The .40 caliber does release more energy but not by a whole lot either. The 9mm releases about 10 - 12 % less energy than its competitor. Also, there are ammo manufacturers that say their 9mm can match up in stopping power against other 40 cal. rounds In ballistic gels. 



Now, this is just ballistics that we are talking about. Let’s talk about what many people think of when it comes to concealed carry. 


9mm ammo is well liked by the majority for many reasons. One being its popularity. The fact that you can walk into any gun store or sporting goods section and pick up a box makes it suitable for everyday carry. This also allows for many manufacturers to play the “supply and demand” game and bring the price down. The consumer loves this because it allows people to shoot their 9mm loads without breaking the bank. 


Most gun manufacturers use the same 9mm pistol frame for both calibers. Glock is notorious for this. The only difference is the barrel size and magazine. With that being said, the gun chambered in 9mm is going to hold more rounds than the .40 S&W. This is because the .40 cal is a larger round and takes up more space in the magazine limiting its round count lesser than that of the 9mm. 

This argument is usually refuted with “well, if you are shooting a .40 cal, you don’t need that many rounds” This may hold true but remember the ballistics on these 2 rounds, they are not that far apart. Another thing to consider is rapid fire. The .40 cal kicks harder than the 9mm. This may be a downside when trying to come up on your target for a follow-up shot. 


It’s all gonna come down to what you feel is best for you. More rounds when carrying? More knock-down power? Will you be ok with more recoil? What about price and availability? Try them both out if you get a chance.


At the end of the day, it comes down to one question, “Are you carrying?


Know your state and local laws. Do your due diligence. Train and know your gun safety rules and start carrying. 


Thanks for your time,


Rene Aguirre

Rene Aguirre is the founder and owner of Bravo Concealment. Rene has been carrying concealed on a daily basis for over 8 years and has been a CHL (concealed handgun license) holder for more than 20 years. Finding a high interest in firearms for many years, Rene started Bravo because of the “lack of” a good concealed carry holster on the market.


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  • If I’m using a small ccw I want nothing larger than 9mm. If it is a full sized weapon that has some weight to help manage recoil 40 S&W.

    Gun Crazy Dec 14, 2021
  • If I’m using a small ccw I want nothing larger than 9mm. If it is a full sized weapon that has some weight to help manage recoil 40 S&W.

    Gun Crazy Dec 20, 2021
  • I grew up in an era when you had 2 choices, 38-357 or 45. I find the 40 a great comprise. Since I reload for both, even better. I also have a fondness for the 45 GAP !

    Will Mar 23, 2023
  • I see these comparisons far too often. They never seem to give the 40 the credit it deserves. Before I get into it let me start by stating that I like 9mm and 40 and own plenty of guns chambered in both. I also reload for both and know the limits of each cartridge. I am lucky enough to own my own shooting range which enables me to perform various test. Now, the difference between these two cartridges has been rumored to be negligible. This is only true for the watered down crappy factory defense loads. Comparing apples to apples, or best to best the scale shifts in favor of the 40 quickly. I can back my claims with facts and science. The best(most energetic) 9mm I can find is loaded by none other than Underwood. This load is a 115 hp at 1400 FPS. This equates to just over 500 fpe. That’s a respectable number. Keep in mind this is a p load so it’s not for every gun and it’s recoil will be noticeable sharper than standard 9mm. Now you know the hottest 9 load on the market let’s discuss the hottest 40 S&W load. It too is brought to us by Underwood. It’s a 135 gr hp traveling 1400 FPS. This is not p, in fact it’s not even max pressure which is 35k. So the 40 can produce nearly 600 fpe and can easily exceed that with proper hand loads. This is more powerful than most 357 mag loads, and it’s a larger diameter bullet. I have loaded 135 and 155 grain 40 loads to exceed 650 fpe. I have a max pressure load for my USP, P226, and XDM that pushes a 135 gr to over 1500 FPS. It takes a longer barrel granted but that’s well into 10mm auto territory. I’ve yet to see any ill effects to my guns or brass. I only fire this max pressure load in my full sized 40’s with upgraded recoil springs and fully supported chambers. No 9mm or even 45 acp can reach this level of power. With exception of the 45 super, which in my opinion is the king of semi-auto pistol calibers. So if one compares the best of each offering you can see the 40 is the clear winner. You get magnum performance in a small package. Feel free to fact check me. The 40 is in my very unbiased opinion the best all around self defense cartridge for concealed carry, especially in smaller single stack guns. For larger home defense or combat sidearms I would say the 40 is great option, but 10mm and 45 super are an even better option.

    Rane Aug 01, 2020
  • Ignorant statements about men being like women and needing less recoil shows someone who lacks confidence.

    The truth is, as a 9mm CCW fan I prefer more rounds

    Ian Dominguez Apr 23, 2020

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