.40 S&W vs. .45 ACP

.40 S&W
.45 ACP

The .40 S&W was developed specifically for law enforcement needs. It fires rimless, .40 inch (10.16mm) diameter bullets. The .45 ACP (Automatic Colt Pistol) uses bullets with diameters of .452 inches (11.5mm). The energy of the .40 S&W exceeds standard-pressure .45 ACP loadings, generating between 350-foot-pound (470 J) and 500-foot-pound (680 J) of energy, depending on bullet weight.

Comparison chart

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.40 S&W

User Rating (223):

.45 ACP

User Rating (155):
Bullet diameter 0.4 in (10.2 mm) .452 in (11.5 mm)
Neck diameter .423 in (10.7 mm) .473 in (12.0 mm)
Base diameter .424 in (10.8 mm) .476 in (12.1 mm)
Case type Rimless, straight Rimless, straight
Rim diameter .424 in (10.8 mm) .480 in (12.2 mm)
Place of origin United States United States
Case length .850 in (21.6 mm) .898 in (22.8 mm)
Designer Smith & Wesson John Browning
Overall length 1.135 in (28.8 mm) 1.275 in (32.4 mm)
Velocity 900-1449 FPS 700 - 1150 FPS
Cost More expensive than 9mm, cheaper than .45 More expensive than .40 S&W and 9mm
Designed January 17, 1990 1904
Maximum pressure 35,000 psi (240 MPa) 21,000 psi (140 MPa)
Penetration 9.8-25.0” 11.3-27”
Variants None .45 ACP +P, .45 Super
Used by United States and others United States and others
Expansion 0.40 – 0.76” 0.45-0.79”
Case capacity 19.3 gr H2O (1.255 cm³) 25 gr H2O (1.625 cm³)
Primer type Small Pistol primarily large pistol (but also small pistol in some brass)
Felt Recoil "sharp and snappy" and slower to get back on target for follow up shots. Heavier and pushes one's hands backwards instead of up. Does not have much muzzle flip.
Rifling twist 1 in 16 in. (406 mm) 1 in 16 in (406 mm)

Contents: .40 S&W vs .45 ACP

Sig Sauer P220 .45 ACP
Sig Sauer P220 .45 ACP

edit Production History

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

The .45 was developed by John Browning in 1904. It has been used by the United States and other militaries since World War I.

edit Evolution

After the 1986 FBI Miami shootout, where two FBI agents were killed due to lack of adequate power exhibited by their service .38 Special handguns, the FBI started looking for a replacement handgun. They needed something with an increased ammunition capacity, easier reload and reliably functions with a reduced velocity 10mm ammunition (something between the .45 and 10mm). S&W then developed .40cal which matched the performance of a 10mm and could be retrofitted into medium-frame (9mm size) automatic handguns.

During the early 20th century wars (The Philippine–American War, World War I etc), rifles like double action revolvers in .38 Long Colt and .303 British were not proving effective in stopping opponents. After a few tests, the Army and the Cavalry to decide that a minimum of .45-caliber was required in the new handgun. The Cavalry asked for a .45-caliber equivalent Colt modified the pistol design to fire a .45-caliber version of the prototype .41-caliber round. The result from Colt was the Model 1905 and the new .45 ACP cartridge.

edit Usage

.40 cartridges are 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.”

.45 is a very popular choice for personal defense during a home invasion and in law enforcement.

This video discusses in detail about .40 vs .45 for home defense:

edit Size

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.

The .45 has a bullet diameter of 11.5 mm (.452 in), a neck diameter of 12.0mm, a base diameter of 12.1 mm, and a rim diameter of 12.2 mm.

A line-up of pistol and rifle cartridges. From left to right: 9mm 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: 9mm 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.

edit Cost

A .45 ACP is anywhere between 20% and 60% more expensive than a .40.

edit Magazine capacity

Due to the smaller size of the bullet, .40 ACPs typically have a higher magazine capacity than a .45, although the specifics vary depending on the type of gun.

Example: A Glock .40 pistol such as the 35,22,23 & 27 models can hold upto 31 rounds of .40 S&W. A few .45 ACP handguns like HS2000 can hold as many as 14 cartridges. The FNP-45 can hold upto 15 .45 cartridges but this greatly increases the pistol's bulk and hence lowers maneuverability.

edit Velocity

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

A .45 fires bullets with an average velocity between 835 and 1150 feet per second.

edit Accuracy

While the accuracy depends on several factors like the skill of the shooter, the gun used, the size of the barrel, wind velocity etc. at shorter distances (10-20yards), both have nearly equal accuracy. At longer distances, the velocity of the bullet matters. Since .45 has a lower velocity, it has the trajectory which needs to be take into account while firing.

edit Penetration

A typical .40 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”.

A .45 averages about 11.3”-14.3” penetration. However, the Remington FMJ has 27” penetration. The cartridge expands to an average of 0.75” inches, but the Remington FMJ expands to 0.45”.

edit Recoil

The felt recoil for a .40 is much more than a .45.

People who have used both these guns have described .40 recoil as "sharp and snappy" and slower to get back on target for follow up shots. [1].

The .45 recoil seems to be heavier and pushes one's hands backwards instead of up. It does not have much muzzle flip. [2]

edit References

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Comments: .40 S&W vs .45 ACP

Anonymous comments (5)

May 4, 2014, 5:32pm

A 180 grain .40 S&W travelling at 1017 fps has the same kinetic energy as a 230 grain .45 ACP @ 900 fps.
For bullets of the same design, e.g. FMJ, the .45 has 13% more momentum than the .40 at these muzzle velocities.
This should result in greater penetration in various medium types- I.e. ballistic gelatin.
Recoil, at least on paper, favors the .40.
However, the weight of the pistol used, the type of powder, and how long the bullet stays in the barrel before exiting all play a role in felt recoil.
The upshot is that with recent bullet design improvements, the shooter now has several choices of calibers that produce near identical terminal ballistics.
And if there is any doubt, use a shotgun loaded with 00 Buck.

— 107.✗.✗.116

February 18, 2014, 2:49am

Actually 40 is a higher energy round

— 67.✗.✗.27

April 15, 2014, 3:59pm

None of this matters to me i can shoot a pistol gripped 12ga. one handed..pistol style.

— 174.✗.✗.48

February 22, 2014, 10:08pm

The hot loaded .45s produce more energy than hot loaded .40s. That is a fact check ballistics.org. Kim is right overall. The .40 caliber is honestly one of the more useless calibers. The new 9mm rounds are superior to the .40 and have more rounds. I prefer the .45 to either. Not to mention the high pressure .40 wears the gun out faster. The .40 is really weak when compared to the 10mm. I don't see a point in the .40, is no better than a 9 and not better than a .45. And certainly not better than the 10mm,

— 69.✗.✗.252

June 2, 2014, 11:01pm

Even with FMJ, the .45 ACP makes nice big round holes! In a shooting, a lawyer could say you wanted to kill because you used evil, nasty, horrible, hollow points which are outlawed international agreement instead of hard ball which the military uses.

— 108.✗.✗.46


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