.40 S&W Ammo

40 S&W

.40 S&W: In Depth

In the wake of a famous 1980s tragedy, the FBI performed a series of ballistics gel tests with multiple handgun calibers in order to home in on the best possible cartridge for their agents. The contest primarily pitted 9mm Luger vs .45 ACP, however, the FBI also tested hand-loaded, down-powered 10mm Auto rounds, which seemed to check every box in the test. Upon seeing the superior performance of this 10mm load compared to the other cartridges in the test, they approached Smith and Wesson to produce a handgun that would effectively fire this modified 10mm Auto ammunition and also fit the various requirements of the bureau for a service pistol.

S&W quickly realized during development of this pistol that the generous case capacity of the 10mm Auto was essentially wasted on the FBI’s modified load, and that this consequently left an opportunity for them to produce something ballistically similar in a smaller sized case. They would furnish the FBI their desired pistol – the Model 1076 – in 1989, and continue to work on their own cartridge in the meantime. It wasn’t long after, in coordination with ammunition manufacturer Winchester, that S&W announced the .40 S&W cartridge at SHOT show in 1990. The new round’s size put it right in the middle of 9mm Luger and .45 ACP, and seemingly combined the benefits of both calibers – the smaller size of the .40 S&Ws ammunition meant existing 9mm pistol frames could be used, while its “stopping power” more closely mimicked that of .45 ACP. At the time, Smith and Wesson also announced a semi-automatic pistol – the Model 4006 – along with their new cartridge. As it turned out, up-and-coming manufacturer Glock got hold of the new ammunition somehow and was able to adapt their 9mm Luger pistol design to the new .40 caliber round. Both the Glock 22 and Glock 23 would beat S&W’s pistol to market later that same year. 

Meanwhile, in FBI land, poor performing 1076s chambered in 10mm Auto had the bureau rethinking their choice to move to the new pistol, and cancellation of the 9,500-unit contract with Smith and Wesson ensued before even a third of the guns had been fulfilled. The FBI moved back to SIGs chambered in 9mm while they considered what to do next. The release of the .40 S&W must've chafed them a bit – it being so similar to their own pet 10mm Auto load. .40 S&W also had a distinct size advantage over 10mm Auto, since smaller pistol frames could be used. For whatever reason, they waited until 1997 to “officially” adopt .40 S&W, and like many law enforcement organizations around the country, chose to issue Glock pistols to their agents when they made the switch.

Starting in earnest a few years after its release, .40 S&W began a popularity streak with law enforcement that would last for a few decades. Along with the size and magazine capacity benefits that were present from the beginning, the cartridge could accept a healthy variety of bullet weights. Besides the standard 180-gr. loading, 165-gr. loads were also developed in both subsonic and supersonic velocity ranges. These 165-gr. loads continue to be among the best selling for the cartridge. Even lighter bullets in the 135-gr. to 155-gr. range also worked well, and all of these were still heavier than the standard 115-gr. or 124-gr. 9mm loads, resulting in more energy delivered downrange. At the same time, the middle ground that the .40 S&W seemed to occupy was making it an appealing choice for concealed carry. .40s were easier to conceal than .45s, and lighter, too.

However, many of the same innovations in bullet technology that propelled the .40 S&W into widespread LE adoption and concealed carry dominance would eventually lead shooters back to 9mm Luger – chiefly the modern hollow point designs. These designs, coupled with advanced powders that performed well in shorter barrels, led to a 9mm round that had nearly identical terminal performance, a lot less recoil, and could be double stacked in smaller magazines. Smaller and lighter was going to win out in the end.

Though many LE agencies have pivoted back to 9mm Luger, and concealed carriers far and away seem to prefer the smaller caliber as well, .40 S&W still has the essential traits that made it popular in the first place – a hefty bullet with plenty of stopping power in a smaller package than .45 ACP. Many .40 cal devotees won’t even consider carrying a smaller round. Provided that you’re not overly sensitive to recoil and don’t mind a bit of bulk compared to 9mm, you might become a devotee yourself. 

.40 S&W: Guns

The .40 S&W gun market consists mainly of duty-sized and compact semi-auto pistols. PCCs and PDWs are a more recent addition. Pistols chambered for this cartridge are generally the same size as their 9mm Luger counterparts, so it's common to see both .40 S&W and 9mm Luger offerings of the same model. Note: while this was a given back in the 90s and early 2000s, many pistol manufacturers are no longer chambering for .40 S&W. In addition, LE trade-in pistols are still commonly found on the used market and are both a solid and inexpensive choice for a duty-sized carry or home-defense gun.

Semi-Auto Pistols

  • Glock 22
  • Springfield Armory XD Tactical
  • S&W M&P40 Shield
  • Taurus G2C

Semi-Auto PDWs and Carbines

  • Armalite M-15 PDW
  • CMMG Banshee MkGs Pistol
  • Kel-Tec Sub2k
  • Ruger PC Carbine
  • Hi-Point Carbine

Why Choose .40 S&W?

This is a self-defense and concealed carry round more than anything else. Although some are quick to point out its shortcomings, there’s absolutely nothing weak about this cartridge – it’s got a ton of energy – anywhere from 30 to 100 ft/lbs more at the muzzle than 9mm Luger, depending on the load. And, while some folks use .40 S&W to hunt hogs, and it certainly can be used to put down a variety of other animals, hunting ammo selection is quite limited, in general. Due to the fact that LE / military cartridges get the most attention among the shooting public here in the US, this round has been popular for recreational target shooting for many years, and there are tons of FMJ loads available for plinking or training. These, however, are not as cheap to shoot as similar 9mm Luger offerings. 


  • This modern round was designed with self-defense, LE duty carry, and concealed carry in mind.
  • More energy than 9mm Luger, smaller package and more magazine capacity than .45 ACP.


  • While it may have more recoil than 9mm Luger, it can also be more fun to shoot!
  • Plenty of FMJ loads with either 165-gr. or 180-gr. bullets designed for target shooting.
  • Bulk ammo is more expensive than similar 9mm Luger.

.40 S&W: Ammo Brands and Loadings

This handgun cartridge is all about self-defense, so likewise, it's all about hollow points. Bullets will either be JHPs or some form of truncated cone / flat nose construction, since a round nose would make the COAL (cartridge overall length) too long to fit in a magazine. Grain weights range anywhere from 9mm Luger territory all the way to the lower end of 10mm Auto, but the most common by far are the 165-gr. and 180-gr. projectiles. There are also a handful of loads that are designed to hunt small-to-medium sized game, like hogs.


Standard Loading

  • 180-gr. JHP or FMJ @ 1,000/fps

Bullet Types

  • JHP (Jacketed Hollow Point) - Self-defense
  • FMJ (Full Metal Jacket)  - Target, training
  • HP Lead Free  - Self-defense
  • Monolithic / Penetrator  - Self-defense w/ barrier penetration
  • Frangible - Target, training

Bullet Weights

  • 125-gr. to 155-gr. - Specialty / lead-free HPs
  • 165-gr. - Self-defense, target 
  • 180-gr. - Self-defense, target 
  • 200-gr. and up -  Hard-cast lead loads


  • 125-gr. to 155-gr. - 1,050/fps to 1,400/fps
  • 165-gr. - 1,050/fps to 1,150/fps
  • 180-gr. - 1,000/fps
  • 200-gr. and up -  850/fps to 1,000/fps

.40 S&W: Frequently Asked Questions

Yes. It’s a powerful handgun cartridge that doesn’t require you to step up to .45 ACP or 10mm Auto sized pistols. From the beginning, this round has been a good compromise between the high capacity benefit of 9mm Luger and the heavy thump of .45 ACP. While .40 S&W produces more recoil than 9mm Luger, it also delivers more energy to the target.

This round is definitely powerful enough for home-defense. By and large, the same loads that are effective for concealed carry purposes are also good for home-defense (rapid expansion). Some folks might benefit from a heavier pistol for home-defense if running .40 S&W, since the recoil of this round is stouter than 9mm Luger’s.

Most people stick to hogs if they’re hunting with this round. Like most handgun cartridges, the question here (besides legality in your area) isn’t “can you?” as much as “should you?”. 

No. They are both .40 caliber, but nowhere close to the same round and not interchangeable.