Differences between .40 S&W and 9mm
Contents
.40 S&W vs. 9mm Parabellum[edit]
The .40 S&W and 9mm Parabellum are two of the most common centerfire pistol cartridges in the world.[1] The 9mm was developed by Georg Luger in 1901 and became one of the most widely adopted military and law enforcement cartridges globally.[2][1] The .40 S&W was introduced in 1990 through a collaboration between Smith & Wesson and Winchester.[3] It was developed in response to the FBI's search for a cartridge with more terminal ballistic effect than the 9mm ammunition used during the 1986 FBI Miami shootout.[4][3]
For decades, the .40 S&W was a popular choice for law enforcement agencies in the United States.[5] However, with advancements in bullet technology that improved the performance of 9mm projectiles, many agencies have returned to the 9mm.[5] The FBI officially began a transition back to 9mm in 2015, citing the ability of agents to shoot the lower-recoil 9mm more accurately and quickly, as well as the cartridge's higher magazine capacity and lower cost.
Comparison Table[edit]
| Category | .40 S&W | 9mm Parabellum |
|---|---|---|
| Bullet Diameter | .400 in (10.2 mm) | .355 in (9.01 mm)[2] |
| Typical Bullet Weight | 165–180 gr (10.7–11.7 g) | 115–147 gr (7.5–9.5 g) |
| Case Length | .850 in (21.6 mm) | .754 in (19.15 mm) |
| [2]Magazine Capacity | Lower (e.g., 15 rounds in a Glock 22) | Higher (e.g., 17 rounds in a Glock 17) |
| Recoil | Higher; often described as "snappy" | Lower; allows for faster follow-up shots |
| Muzzle Energy (Typical) | ~350–500 ft⋅lbf (470–680 J) | ~320–420 ft⋅lbf (430–570 J) |
| Ammunition Cost | Generally higher | Generally lower |
Performance Characteristics[edit]
A primary difference between the two cartridges is felt recoil. The .40 S&W is a higher-pressure round and produces more recoil energy than the 9mm, which some shooters find difficult to manage. The lower recoil of the 9mm generally allows for faster and more accurate follow-up shots. This difference in "shootability" is a significant reason why law enforcement agencies have trended back toward the 9mm.
Due to its smaller physical dimensions, 9mm pistols of a similar size to their .40 S&W counterparts can hold more cartridges. For example, a full-size Glock 17 (9mm) holds 17 rounds, while the comparable Glock 22 (.40 S&W) holds 15 rounds.
Historically, the .40 S&W was considered to have superior "stopping power" due to its larger diameter and heavier bullet, which creates a larger wound cavity. However, improvements in the design of modern hollow-point ammunition have increased the effectiveness of the 9mm, narrowing the terminal performance gap between the two. Both cartridges, when[5] using quality defensive ammunition, are capable of meeting FBI standards for penetration.
Ammunition for the 9mm is typically less expensive and more widely available than .40 S&W, partly due to its use by militaries worldwide, including as the standard NATO handgun round.
References[edit]
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References[edit]
- ↑ 1.0 1.1 1.2 "wikipedia.org". Retrieved December 02, 2025.
- ↑ 2.0 2.1 2.2 "ammunitionsforsale.com". Retrieved December 02, 2025.
- ↑ 3.0 3.1 "wikipedia.org". Retrieved December 02, 2025.
- ↑ "pd-ammo.com". Retrieved December 02, 2025.
- ↑ 5.0 5.1 5.2 "firearmslegal.com". Retrieved December 02, 2025.
