9mm vs 40 S&W: Ultimate Comparison [2023]

March 06, 2023 4 min read

Introduction: 9mm vs .40

When it comes to choosing the right cartridge for your firearm, there are several factors to consider. Two of the most popular options are .40 S&W and 9mm cartridges. While both are effective choices for self-defense and target shooting, there are some key differences between the two. In this article, we'll explore those differences in detail to help you make an informed decision.


Overview of .40 S&W and 9mm Cartridges

Before we dive into the specifics, let's start with an overview of .40 S&W and 9mm cartridges. .40 S&W, also known as .40 Smith & Wesson, was developed in 1990 as a law enforcement cartridge. It's a rimless, straight-walled cartridge that's roughly the same length as a 9mm cartridge but wider in diameter. It typically fires a bullet that weighs between 135 and 180 grains, meaning it is a heavier bullet than the 9mm cartridge.

9mm loads, also known as 9x19mm Parabellum, are one of the most popular cartridges in the world. It's a rimless, bottlenecked cartridge that was developed in 1902 for use in the Luger semi-automatic 9mm pistols. It fires a 115 to 147 grain bullet.

.40 S&W and 9mm ammunition are both popular cartridges used in handguns for self defense, FBI agents, law enforcement agencies, police departments, and military applications.

Detailed Comparison Between .40 S&W and 9 mm Ammo

The .40 S&W was designed by Smith & Wesson in 1990 as a shorter and less powerful version of the 10mm Auto cartridge. It has a bullet diameter of 0.4 inches and a case length of 0.85 inches. The maximum pressure for the .40 S&W is 35,000 psi, and it can reach velocities of 900-1449 FPS. The .40 S&W has a reputation for being "sharp and snappy" with more felt recoil than the 9mm, which can make it slower to get back on target for follow-up shots. However, it generally offers more penetration than the 9mm, with a range of 9.8-25.0 inches. The .40 S&W is also more expensive than the 9mm, but cheaper than the .45 ACP.

The 9mm, also known as the 9mm Luger or 9x19mm Parabellum, was designed by Georg Luger in 1901. It has a 9.01 mm bullet diameter and a case length of 19.15 mm. The maximum pressure for the 9mm is 235 MPa (34,084 psi), and it can reach velocities of 950-1400 FPS. The 9mm generally has less felt recoil than the .40 S&W, making it easier to get back on target for follow-up shots (better shot placement). Using ballistic gel, it can offer penetration in the range of 8-40 inches (or 13 feet). The 9mm is also cheaper than the .40 S&W and .45 ACP, which is a good reason to choose 9mm caliber pistols if you are planning to do more shooting practice with this pistol than using it for a self-defense situation.

Both cartridges are used by various military, law enforcement, and self defense applications. The .40 S&W is primarily used by the United States and other countries, while the 9mm is used by NATO and many other countries. The .40 S&W is primarily used in pistols, while the 9mm can also be used in revolvers, carbines, submachine guns, and derringers.

Ballistics Comparison

One of the most significant differences between .40 S&W and 9mm cartridges is their ballistics. Ballistics refers to the behavior of the bullet in flight, including its velocity, trajectory, and energy. In general, .40 S&W cartridges have more energy and stopping power than 9mm cartridges, which makes them a popular choice for law enforcement and self-defense.

However, this increased stopping power comes at a cost. .40 S&W cartridges have a higher recoil and muzzle flip, which can make them more challenging to control. Additionally, they tend to be more expensive than 9mm cartridges, which can be a factor for target shooters who go through a lot of rounds.

On the other hand, 9mm cartridges are known for having less recoil, making them easier to control for many shooters. They also tend to be less expensive than .40 S&W cartridges, making them a popular choice for target shooting and plinking.

Accuracy comparison

Another essential factor to consider when choosing a cartridge is accuracy. The accuracy of a cartridge is affected by several factors, including the gun's design, the shooter's skill, and the cartridge's ballistics. In general, .40 S&W cartridges are known for their accuracy, thanks to their flatter trajectory and increased energy.

However, 9mm cartridges are no slouch in the accuracy department either. In fact, many expert marksmen prefer 9mm cartridges for their accuracy and precision, especially at longer ranges.

Terminal Ballistics Comparison

The terminal ballistics of a cartridge refer to its behavior upon impact with a target. This includes factors like penetration, expansion, and energy transfer. In general, .40 S&W cartridges have better terminal ballistics than 9mm cartridges, thanks to their increased energy and stopping power.

However, modern 9mm cartridges have come a long way in recent years, with many manufacturers producing high-quality hollow point rounds that deliver excellent terminal ballistics. This has made 9mm cartridges a popular choice for self-defense and law enforcement, thanks to their lower recoil and higher magazine capacity.


Both .40 S&W and 9mm cartridges have their advantages and disadvantages, and the choice between the two depends on your individual needs and preferences. If you're looking for a cartridge with increased stopping power and don't mind the higher recoil and cost, .40 S&W caliber handguns might be the right choice for you. However, bigger bullets do not always win against the bad guy. A 9mm handgun like the SIG Sauer P320 or SIG P365 can give you an extra few shots. Carefully choosing your bullet weights, bullet design, and using higher pressure 9mm rounds can give you a similar kinetic energy and muzzle energy. If you're looking for a cartridge with low recoil, increased capacity, and excellent accuracy, 9mm might be the way to go.

When it comes to choosing a cartridge, there is not one clear winner. It's essential to consider all the factors that can impact your decision, including ballistics, accuracy, and terminal ballistics. By doing your research and considering your individual needs and preferences, you can make an informed decision and choose the cartridge that's right for you.