.40 s&w Handgun Cartridge
The .40 caliber parent case - 10mm
The .40 s&w cartridge
The .40 s&w cartridge has been a popular round since it was developed in January 1990 with law enforcement agencies throughout the United States, Canada, and Australia. It is also a popular round with those that hand land their own ammunition. The cartridge was developed by the FBI from the parent 10mm cartridge in the 1968 Miami shootout.
It was a round that was designed specifically for law enforcement purposes from the 10mm round but with less recoil. Although developed from the 10mm round it has a shorter case length and shorter overall cartridge length.
As an owner of a Glock 22 I have put hundreds if not thousands of rounds through it from many manufacturers and have never once had any malfunctions with the ammunition. I also occasionally handload my own ammo and have never had any problems with any of those rounds either.
Other Names for .40 s&w
- .40 Auto
- .40 caliber
- "Forty Cal"
A Few Common Ammo Terms
Cartridge = the entire piece of ammunition (bullet, case, jacket, primer, and charge)
Bullet = the projectile that is the projectile that comes out of the end of the gun through the barrel when the gun is fired.
Case = the largest part of the round that holds the bullet, contains the charge, and hoses the primer.
Primer = the part at the opposite end of the bullet that is a tiny circle that the firing pin in the gun strikes which when struck will ignite the powder inside the case.
Charge = is the propellant inside the case that when ignited creates pressure that causes the bullet to travel through the barrel and out of the gun.
.40 Caliber Ammo Box
.40 S&W Specifications
Bullet diameter .4 in (10 mm)
Rifling twist 1 in 16 in. (406 mm)
Maximum pressure 35,000 psi (240 MPa)
Parent case: 10mm Auto
Case length .850 in (21.6 mm)
Case type: Rimless, Straight
Overall length 1.135 in (28.8 mm)
Primer type Small Pistol
Performance Table of Specific Manufacture Ammo*
135 gr (9 g) Federal Premium JHP Reduced Recoil
1,190 ft/s (360 m/s)
424 ft·lbf (575 J)
155 gr (10 g) Guardian Gold JHP
1,205 ft/s (367 m/s)
500 ft·lbf (680 J)
165 gr (11 g) Remington Golden Saber
1,150 ft/s (350 m/s)
485 ft·lbf (658 J)
180 gr (12 g) Magtech FMJ-FP
1,050 ft/s (320 m/s)
441 ft·lbf (598 J)
40 caliber ammunition bought in stores usually comes in 50 or 100 round boxes and price ranges from $15-$40. And can be bought in most outdoors stores, retailers like Walmart, and local firearms stores.
Common manufacturers that can be found in retail stores:
Types of Ammunition
Jacketed Hollow Point (JHP)
Full Metal Jacket (FMJ)
Use by Law Enforcement
The .40 caliber round has been a very popular round for many law enforcement agencies across the United States from Federal Agencies, State and local law enforcement.
State Law Enforcement
- Alaska State Troopers
Federal Law Enforcement
- Federal Bureau of Investigation
- United States Drug Enforcement Administration
Which round would you prefer for home defense?
.40 Cailber For Self-Defense Review
The .40 caliber round is also a good round for self or home defense as it has higher velocities than the .45 ACP with less recoil and similar energies as the ,45 ACP with certain manufactured rounds.
With velocities ranging from 950 ft/s to upwards of 1,400 ft/s, energy ranging from 500 to 850 ft·lb, expansion ranging from 0.40 in (10 mm) to 0.76 in (19 mm), and penetration ranging from 9.8 in (24.9 cm) to 25.0 in (63.5 cm) the .40 caliber round makes a very effective personal defense round
I also own a Glock 23 for concealed carry purposes and at first was worried that the .40 caliber round in a compact gun would be a little hard to control, however I have found that it is comparable to a 9mm in a compact gun. To me it is a great round for defense purposes whether in a compact or full size firearm.
When purchasing ammunition for personal defense it is common to see boxes labeled with terms such as critical defense or ultimate defense and will usually come in 20 round boxes ranging from around 165 - 180 grains. They will also carry a slightly higher price tag as well, which in my opinion makes it all the more reason not to purchase these rounds marketed as "personal defense" rounds because the same ammunition can be purchased without that "personal defense" label stamped on the box for about the same price, but you will get 50 - 100 rounds.
How the .40 Caliber Came about
9mm vs .40 s&w vs. .45 ACP
Bullet diameter: 9.01 mm (0.355 in)
Bullet diameter: .4 in (10 mm)
Bullet diameter: .452 in (11.5 mm)
Case length: 19.15 mm (0.754 in)
Case length: .850 in (21.6 mm)
Case length: .898 in (22.8 mm)
Overall length: 29.69 mm (1.169 in)
Overall length: 1.135 in (28.8 mm)
Overall length: 1.275 in (32.4 mm)
Primer type: Small pistol
Primer type: Small Pistol
Primer type: Large or Small pistol