9mm vs. 40 S&W: Ending the Concealed Carry Debate

By Wes Littlefield

Last Updated: Apr 20, 2026

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Wes Littlefield

Guns have fascinated Wes since pulling the trigger on his BB gun as a kid. He built a private gun range over a decade ago to keep his skills sharp. He loves breaking down complex ideas into understandable pieces for readers, with expertise in hunting and all aspects of shooting.

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Wes Littlefield, "9mm vs. 40 S&W (Which Should You Carry in 2026)"
(https://ammo.com/comparison/9mm-vs-40)

The 9mm vs. 40 Smith & Wesson (40 S&W) debate has been raging since the introduction of 40 S&W ammo in early 1990. The debate centers around which of the two pistol cartridges is superior for concealed carry.

Let’s take an objective look at the 40 S&W and see how it stacks up against 9mm ammo – the most popular centerfire handgun round in the world.

I hope you have a full pack of silhouette targets and several boxes of FMJ ammo. You’re going to need them as we take our shot at the 40 S&W vs. 9mm personal defense ammo debate!

40 S&W vs. 9mm: The Differences Between 40 and 9mm

Let’s start with the top three points of contention when it comes to the 40 S&W vs. 9mm discussion: stopping power, magazine capacity, and recoil.

9mm vs. 40: Stopping Power

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Stopping power (aka knockdown power) is one of those ambiguous terms shooters like to throw around to justify their position on one cartridge or another. There is no column on the ballistics charts for stopping power. In truth, it is a combination of several factors including striking energy, wound cavity diameter, penetration depth, and shot placement.

Although stopping power cannot be quantified, it is essentially the rate at which the bad guy reaches a state of incapacitation. Once the threat is unwilling or unable to continue, you’ve survived the fight.

A 40 S&W to the foot is a lot less lethal than a 9mm to center mass. However, with all other things being equal, the 40 S&W is going to hit harder and cause a larger permanent wound cavity as it is loaded with a wider and (usually) heavier bullet compared to a 9mm.

The 9mm diehards are going to expound on the fact that advancements in JHP technology have brought the 9mm round to the same level as the 40 S&W in terms of terminal expansion. I’m not sure if I’m willing to go that far.

It cannot be denied that a 40 S&W will cause a larger permanent wound cavity and exhibit better terminal performance than a 9mm, but the average shooter typically has better shot placement with the 9mm. The 40 S&W only edges out the 9mm by a hair.

The biggest issue many detractors of the 40 S&W bring up is the amount of recoil the cartridge has, which will directly affect shot placement.

On that note, let’s discuss recoil!

9mm vs. 40: Recoil

The 40 S&W is difficult for many shooters to handle due to its snappy recoil. 9mm loads have about 25% less recoil than the 40 S&W. For an experienced shooter, that added recoil will not be too difficult to handle. However, for a new shooter or one with smaller hands, it can be incredibly difficult to handle the recoil of a 40 S&W.

No matter how you slice it, a shooter utilizing a 9mm round will experience less recoil. That means they can reasonably expect faster follow-up shots and generally improved accuracy compared to using a 40 S&W.

9mm vs. 40: Magazine Capacity

Magazine capacity for the 9mm and 40 S&W is very good. One draw to the 40 S&W is that you typically get to fire a heavier bullet without having to forfeit more than a few rounds of magazine capacity.

Comparing the 9mm Glock 17 to the 40 S&W Glock 22, the difference in magazine capacity is only two rounds. That’s pretty good.

However, two rounds are two rounds. They could spell the difference between engaging another threat or having to reload.

Though the difference is small, the 9mm does allow for higher magazine capacity. In no uncertain terms, it lets you carry more ammo in the same amount of space (read: in a similarly sized firearm).

9mm Pistol Magazine Capacity Chart

40 S&W Pistol Magazine Capacity Chart

9mm vs. 40: Accuracy

New shooters occasionally ask me if the 9mm is more accurate than the 40 S&W, or vice versa. That’s not really the right question to ask. What they should be concerned about is which round they can fire more accurately.

Accuracy is primarily dependent on the shooter, not the cartridge or the firearm. If all other things were equal, shooters would experience almost identical accuracy between these two rounds.

However, many shooters discover they are more accurate with a 9mm. This is primarily due to the 40 S&W’s aforementioned heavier recoil.

9mm vs. 40: Home Defense and Concealed Carry

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If I had to chose one of these rounds for home defense, it would be the 40 S&W. Engagements inside the home play out over very close distances. Under those conditions, you want the heaviest, most powerful round you can handle while still maintaining shot placement.

The 180 grain bullet provides excellent penetration and kinetic energy transfer into the bad guy without excessive risk of overpenetration that could jeopardize bystanders.

For concealed carry, the 9mm seems like the better option for several reasons.

First, a compact or sub-compact 9mm handgun has less recoil than a 40 S&W of the same size. Generally, this will result in better accuracy, and this is critical when you are out in public. The potential to hit an innocent bystander is higher in a public place. Every bullet you fire has a lawyer attached to it, so you want to make darn sure you hit what you aim at should you have to defend your life outside the home.

The second reason the 9mm is preferred for CCW is its higher magazine capacity. Generally, 9mm magazines have higher capacity than 40 S&W ones, so you can carry a few extra rounds for the same weight. More rounds are always better!

9mm vs. 40: Ammo Price and Availability

At the time of writing, 9mm and 40 S&W ammo are both plentiful with multiple bullet weight options available. The vast majority of 9mm Luger comes in 115, 124, and 147 grain varieties, while 40 S&W is mostly loaded with 165 and 180 grain bullets.

Generally, premium JHP ammo is about $1 per round for both 9mm and 40 S&W. For FMJ practice ammo, you should expect to pay about $0.50 per round for 9mm and $0.60 per round for 40 S&W.  This isn’t a huge difference, but 9mm FMJ ammo is typically cheaper. It’s utilized by the military. The 40 S&W is not.

Buying in bulk is always smart. Make sure to check out our stock of 9mm bulk ammo and bulk 40 S&W ammo!

9mm vs. 40 Ballistics

Our team here at Ammo.com has combed manufacturers’ data to help you compare 9mm vs. 40 S&W. For even more detailed 9mm performance data across additional manufacturers and loads, see our complete 9mm ballistics reference. These tables will allow you to see how your favorite bullet weight compares to others in terms of muzzle velocity, muzzle energy, and trajectory.

Average 9mm Luger Ballistics

Note: This information comes from ammo manufacturers. Actual ballistics obtained with your firearm can vary considerably from advertised ballistics. Also, ballistics can vary from lot to lot with the same brand and type load.

Average 40 S&W Ballistics

Note: This information comes from ammo manufacturers. Actual ballistics obtained with your firearm can vary considerably from advertised ballistics. Also, ballistics can vary from lot to lot with the same brand and type load.

40 Smith & Wesson (40 S&W): A Brief History of the 1986 Miami Shootout Solution

The 40 Smith & Wesson is a relatively new kid on the block when it comes to self-defense handgun cartridges. Introduced in 1990 in a joint effort between Smith & Wesson and Winchester, the 40 S&W was a direct result of the 1986 FBI Miami shootout.

The 1986 Miami shootout is the most analyzed gunfight involving law enforcement in U.S. history, and the genesis of the 40 S&W.

On April 11, 1986, the FBI was involved in a shootout with two serial bank robbers and murderers in Dade County, Florida. Although the FBI agents outnumbered the criminals eight to two, the FBI special agents were severely outgunned, resulting in two agents losing their lives and five suffering injuries after an extended gunfight.

It was determined that the FBI’s 9mm pistols and 38 Special revolvers were ineffective at stopping the criminals, who endured multiple hits and kept fighting.

In the aftermath of the shooting, the FBI performed extensive ballistic studies in which the terminal performance of various 9mm and 45 ACP defense loads in ordnance gelatin (a synthetic representation of human tissue) was evaluated. The search for a new FBI duty handgun round was on. In 1989, the FBI adopted the 10mm Auto.

Although the 10mm Auto sounds great on paper, real-world results told a different story.

The 10mm had amazing results in ballistic gelatin testing, and satisfied all the FBI’s requirements for a new self-defense round. However, agents in the field were having issues handling the 10mm’s punishing recoil. Furthermore, 10mm Auto pistols are heavy and bulky, making them difficult to conceal.

It wasn’t long until an FBI agent with a penchant for reloading came up with a solution. John Hall, the FBI firearms training agent-in-charge, proposed a 10mm Auto cartridge that he had loaded with a reduced powder charge for consideration.

Hall’s 10mm reload fired a 180 grain .40 cal hollow point at a muzzle velocity 1,000 fps (for context, a full-power 10mm cartridge loaded with the same bullet has a muzzle velocity of 1,400 fps). This handload met the FBI’s ballistic gel testing requirements with substantially reduced recoil.

The FBI subsequently contracted Smith & Wesson to modify their existing large frame semi-auto Model 4006 in 45 ACP to fire the reduced power 10mm Auto round.

During the development phase, Smith & Wesson in conjunction with Winchester determined that the reduced-power 10mm left a lot of dead air space inside the cartridge case, as less propellant was required to meet the muzzle velocity requirements.

Testing indicated that this excess space could be removed, allowing the new round to fit in a medium 9mm pistol frame. How much material was removed? Only 3 millimeters!

This has led some shooters to refer to the 40 S&W as the “10mm Lite,” "10mm Short," or “40 Short & Weak.” But trust me – there’s nothing weak about a 40 S&W.

The brand new 40 S&W round was unveiled on January 17, 1990 in conjunction with the new Smith & Wesson 4006 pistol.

Somewhat surprisingly, Smith & Wesson was not ready with production models of the new 4006 chambered in 40 S&W when they announced the new cartridge. This allowed a certain Austrian perfection-seeking firearms manufacturer (Glock) to beat Smith & Wesson to gun store display cases by a week with their new 40 S&W Glock 22 and 23 pistols.

Standard 40 S&W 165 grain full metal jacket (FMJ) ammo attains a muzzle velocity of 1,130 fps and a muzzle energy of 468 foot-pounds (ft-lbs). SAAMI specs for 40 S&W set maximum pressure at 35,000 psi.

After its introduction in 1990, the 40 S&W became extremely popular with law enforcement agencies across North America. Civilians also took note of the new pistol cartridge, appreciating its increased stopping power without very much magazine capacity forfeited in exchange.

Although advancements in hollow point technology have rendered the 40 S&W less favored in the shooting community as of late, is the 40 still relevant?

Let’s look at its main competition.

What Is 9mm? The Austrian Concealed Carry Staple

The 9×19mm Parabellum was designed by Austrian gunsmith Georg Luger in 1901. Luger derived the 9mm Parabellum from his previous design, the 7.65×21mm Parabellum.

Luger presented the 9mm Parabellum to the U.S. military for consideration at the Springfield Arsenal in 1903, in direct competition with Browning's 45 ACP. The 9mm was not adopted by the U.S. military until much later, though it was picked up by the German Imperial Navy and Army in 1904 and 1908, respectively.

The 9×19mm Parabellum is also referred to as "9mm Luger," or simply "9mm." SAAMI specs cite the maximum pressure for 9mm at 35,000 psi. Standard 115 grain FMJ ammo has an average muzzle velocity of 1,180 fps and 355 ft-lbs muzzle energy.

After World War I and through World War II, the 9mm Luger became one of the most popular handgun cartridges in Europe for both military and law enforcement. The United States was late to the party. It clung to the 45 ACP until the adoption of the Beretta M9 service pistol by the U.S. Army in the 1980s. The popularity of the 9mm really exploded in the United States during the 80s and 90s with the introduction of extremely reliable semi-auto pistols such as the Glock 17, SIG Sauer P226, and more recently the Springfield XD and Smith & Wesson M&P.

Fervor for the 9mm has only been bolstered by the U.S. military's adoption of the SIG Sauer M17 and M18 as its new standard issue sidearms for military personnel.

The 9mm has become synonymous with law enforcement and home defense for its high magazine capacity, jacketed hollow point (JHP) bullet's excellent stopping power, and low cost per round.

9mm pistols are easy to come by and relatively inexpensive. All major firearms manufactures offer something chambered for 9mm, including Glock, Smith & Wesson, SIG Sauer, Kimber, Springfield, Remington, Ruger, and Taurus.

The 9mm has truly become the everyday carry (EDC) handgun of choice for those who don't want to carry something snappier and more sizable like a 357 Magnum. With advancements in hollow point technology, the 9mm has solidified itself as the self-defense ammo of choice for the military, law enforcement, and civilians alike.

40 S&W vs. 9mm: Final Thoughts

The 40 S&W and 9mm are two potent self-defense pistol cartridges that will satisfy the needs of almost any civilian or law enforcement agent.

The 40 S&W offers increased stopping power as it fires a wider — and, usually, heavier — bullet, with only minimal loss to magazine capacity. However, the 40 S&W is a high-pressure round. Some shooters may find its snappy recoil uncomfortable and/or uncontrollable, which leads to slower follow-up shots.

The 9mm benefits from added magazine capacity over the 40 S&W, as well as a recoil impulse that is much more controllable in the hands of inexperienced shooters. For those exploring other 9mm alternatives, the 38 Super compared to 9mm presents another viable option worth considering.

But which is better for you?

My recommendation is to head to your local gun range and rent handguns chambered for both. Put a few boxes of FMJ ammo through each and figure out which one you shoot better.

Shot placement is always going to be the trump card when it comes to winning any personal defense situation. You should carry what you shoot best, and never feel underpowered with either of these premier handgun cartridges.

Written by

Wes Littlefield