The 9mm and the 0.40 S&W provide nearly identical accuracy, drift and drop, but the 0.40 S&W has an energy advantage. The .40 S&W was designed such that it could be retrofitted into medium-frame (9mm size) automatic handguns. So most .40 caliber handguns can be easily converted to 9mm for cheaper target shooting with a simple barrel and magazine swap. However, case failure rates are higher when the 0.40 S&W cartridge is adapted for narrower frames meant for the 9mm. The 9mm and the .40 S&W (Smith and Wesson), along with the 0.45 ACP are among the most popular rimless cartridges for handguns.

Comparison chart

.40 S&W versus 9mm comparison chart
Edit this comparison chart.40 S&W9mm
  • current rating is 3.52/5
  • 1
  • 2
  • 3
  • 4
  • 5
(492 ratings)
  • current rating is 3.58/5
  • 1
  • 2
  • 3
  • 4
  • 5
(696 ratings)
Bullet diameter 0.4 in (10.2 mm) 9.01 mm (0.355 in)
Neck diameter .423 in (10.7 mm) 9.65 mm (0.380 in)
Base diameter .424 in (10.8 mm) 9.93 mm (0.391 in)
Case type Rimless, straight Rimless, tapered
Rim diameter .424 in (10.8 mm) 9.96 mm (0.392 in)
Place of origin United States German Empire
Case length .850 in (21.6 mm) 19.15 mm (0.754 in)
Designer Smith & Wesson Georg Luger
Overall length 1.135 in (28.8 mm) 29.69 mm (1.169 in)
Velocity 900-1449 FPS 950-1400 FPS
Maximum pressure 35,000 psi (240 MPa) 235.00 MPa (34,084 psi)
Designed January 17, 1990 1901
Cost More expensive than 9mm, cheaper than .45 Cheaper than .40 S&W & .45 ACP
Used by United States and others NATO and others; Militaries, police, and self defense.
Penetration 9.8-25.0” 8 - 40" (13')
Primer type Small Pistol Berdan or Boxer small pistol
Rim thickness .055 in (1.4 mm) 0.90 mm (0.035 in)
Expansion 0.40 – 0.76” 0.36-0.72"
Case capacity 19.3 gr H2O (1.255 cm³) 0.862 cm³ (13 gr H2O)
Felt Recoil "sharp and snappy" and slower to get back on target for follow up shots. Less recoil.
Type Pistol Pistol / Revolver / Carbine / SMG / Derringer; Cartridge
Produced 1990–present 1902–present
Parent case 10mm Auto 7.65×21mm Parabellum
A handgun that uses 9×19mm Parabellum cartridges.
A handgun that uses 9×19mm Parabellum cartridges.


The 9mm cartridge was designed by Georg Luger in 1901. It has been produced since 1902.

The .40 cartridge was designed by Smith & Wesson in 1990.

Evolution and Usage

The 9mm cartridge was developed from Luger’s 7.65x21mm Parabellum. The bottleneck of that cartridge was removed, leaving a tapered, rimless cartridge. It was adopted by the German Navy in 1904 and the German Army in 1906. It became more popular after World War I and has since become the most common caliber for U.S. law enforcement agencies and for military and law enforcement agencies around the world. It is also popular for self-defense.

The .40 cartridge was developed to the specifications of the FBI, which requested a gun that could reliably function while firing 10mm ammunition. Smith & Wesson realized that a new cartridge using a small pistol primer would be more effective.


The 9mm has a bullet diameter of 9.01mm (0.355 in), a neck diameter of 9.65mm, a base diameter of 9.93 mm, a rim diameter of 9.96mm and a rim thickness of 0.90 mm.

The .40 has a bullet diameter of 10.2mm (.400 in), a neck diameter of 10.7mm, a shoulder diameter of 10.7 mm, a base diameter of 10.8mm, a rim diameter of 10.8mm and a rim thickness of 1.4mm.

A line-up of pistol and rifle cartridges. From left to right: 9 mm Luger Parabellum, .40 S&W, .45 ACP, 5.7x28mm, 5.56x45mm NATO, .300 Winchester Magnum, and a 2.75-inch and 3-inch 12 gauge.
A line-up of pistol and rifle cartridges. From left to right: 9 mm Luger Parabellum, .40 S&W, .45 ACP, 5.7x28mm, 5.56x45mm NATO, .300 Winchester Magnum, and a 2.75-inch and 3-inch 12 gauge.

Magazine capacity

Due to the smaller size of the bullet, 9mm guns typically have a higher magazine capacity than a .40, although the specifics vary depending on the type of gun. For example, the Beretta 92 gun holds 15 rounds of 9mm bullets, while the Beretta 96 holds 12 rounds of .40 bullets. Similarly, the Glock 17 holds a standard 17 rounds of 9mm bullets, while the Glock 22 holds a standard 15 rounds of .40 bullets.


The 9mm and the .40 have almost identical accuracy, drift and drop. In other words, the bullets act similarly in the air, and drift sideways, drop in height and hit targets at a similar rate after being shot.


A 9mm fires bullets with a velocity of between 990 and 1400 feet per second.

A .40 fires bullets with a velocity between 950 and 1440 feet per second, depending on the model.


A 9mm averages between 8” and 15.9” penetration. However, the Winchester FMJ has a penetration of 24.5” and the Doubletap JFN+P trail defense has a penetration of 40”. The cartridge expands to approximately 0.35” to 0.72”.

A typical .40 SW averages between 9.8” and 13.3” penetration. The Winchester FMJ, however, has a penetration of 25”. It expands to between 0.4” and 0.76”.

This video compares the penetration for 0.40 S&W and 9mm bullets:


9mm cartridges are the most popular and common cartridges in the world. They are the predominant cartridge used by United States enforcement agencies. They are also used by individuals for self defense.

.40 cartridges are also popular with law enforcement agencies in the United States, Canada and Australia. They have been called “the ideal cartridge for personal defense and law enforcement.”


Share this comparison:

If you read this far, you should follow us:

".40 S&W vs 9mm." Diffen LLC, n.d. Web. 7 Jul 2020. < >