.40 S&W Ammunition Guide: Ballistics, Usage, and Performance

The .40 Smith & Wesson (S&W) is a rimless pistol cartridge known for its balance between power and manageability. Developed in 1990, the .40 S&W was the result of a collaboration between Smith & Wesson and Winchester. The intention was to create a round with similar ballistic performance to the 10mm Auto, but with recoil levels that were more manageable in a medium-frame pistol. Law enforcement agencies, most notably the Federal Bureau of Investigation (FBI), adopted the .40 S&W for its favorable ballistics, contributing to its widespread use in the United States.

In terms of design, the .40 S&W uses a 10.2x21mm case, bridging the gap between the 9mm and the larger 10mm calibers. The effectiveness of the .40 S&W made it prevalent not just amongst law enforcement, but also among civilian shooters for self-defense and competitive shooting. Despite fluctuations in popularity and the market's varying demand, the .40 S&W has maintained a presence in the ammunition industry, with numerous handgun models crafted to chamber this particular round.

Key Takeaways

  • The .40 S&W cartridge was developed to provide a balance of power and recoil.
  • It gained prevalence in law enforcement and among civilian shooters for various purposes.
  • The ammunition remains a popular choice, with a stable presence in the market.

History and Development

The .40 S&W cartridge is a notable development in firearm ammunition, crafted to meet specific law enforcement needs and marked by its collaboration between major firearms companies.

Origins and FBI Adoption

Smith & Wesson and Winchester unveiled the .40 S&W cartridge in 1990. Its inception followed the infamous 1986 Miami shootout, which prompted the FBI to re-evaluate its standard issue firearms. Seeking a more powerful round that could fit into a 9mm-sized frame, the .40 S&W emerged as a compromise; it delivered similar ballistic performance to the 10mm FBI load but with reduced recoil.

Evolution of the .40 S&W Cartridge

Originally, law enforcement agencies desired a cartridge with the stopping power of the 10mm but with manageability suitable for more agents. The .40 S&W's adaptation over time reflects this, retaining the essential characteristics of the 10mm while increasing reliability. The cartridge has undergone various changes to meet the evolving standards of law enforcement agencies, securing its role as a mainstay in the law enforcement community.

Design and Ballistics

The .40 Smith & Wesson cartridge demonstrates a balance of power and control, designed to meet law enforcement needs. It provides a middle-ground option in terminal ballistics and magazine capacity.

Cartridge Specifications

The .40 S&W is a rimless pistol cartridge jointly developed by Smith & Wesson and Winchester. It was introduced to offer a compromise between the high capacity of the 9mm, the heavy-hitting power of the .45 ACP, and the high velocity of the .357 SIG and 10mm Auto cartridges. Here are specific details about the cartridge's design:

  • Bullet diameter: 0.400 inches (10.2 mm)
  • Case length: 0.850 inches (21.6 mm)

Table of Basic Measurements



Bullet Diameter

0.400 inches (10.2 mm)

Case Length

0.850 inches (21.6 mm)

Overall Cartridge Length

1.135 inches (28.8 mm)

Ballistic Comparison

When comparing the .40 S&W to other cartridges, its ballistics offer a compromise between size, energy, and recoil. Here is a brief comparison of its ballistic characteristics with similar cartridges:

  • 9mm: The .40 S&W generally has more energy and stopping power than the 9mm due to a larger bullet diameter and heavier bullet weight, but with increased recoil.
  • .45 ACP: The .45 ACP has a larger bullet diameter and potentially more stopping power, but the .40 S&W holds more rounds in a similarly sized magazine.
  • .357 SIG: The .357 SIG typically has higher velocity and energy than the .40 S&W, but the latter offers more manageable recoil.
  • 10mm: While the 10mm has more significant energy and potential for terminal performance, the .40 S&W operates at lower pressures, making it more suitable for a wider range of firearms and shooters.

Ballistic Energy Comparison


Muzzle Energy (ft-lbs)

.40 S&W




.45 ACP


.357 SIG




The .40 S&W's performance is influenced by its moderate case capacity, which balances velocity and energy while maintaining manageable recoil compared to more powerful cartridges. Its design has made it a longtime favorite for self-defense and law enforcement applications.

Usage and Performance

The .40 S&W cartridge has been recognized for balancing stopping power with manageable recoil, making it suitable for law enforcement and self-defense applications. Its performance in various pistols shows why it became a standard in many agencies and among civilians for personal protection.

Law Enforcement Applications

Law enforcement agencies widely adopted the .40 S&W shortly after its introduction due to its higher stopping power compared to the 9mm and its lower recoil compared to the 10mm. The .40 S&W cartridge was standard issue in numerous police departments, often loaded into high-capacity pistols manufactured by Glock, among others.

Pistol Preference: Law enforcement officials appreciated the Glock's dependability when chambered in .40 S&W. The medium-frame size allowed for substantial magazine capacity without significantly increasing the weight or reducing handling efficiency.

Police Trade-ins: As agencies transition to different calibers, the market has seen an influx of police trade-in .40 S&W pistols. These weapons maintain their durability and readiness for continued use beyond their service in law enforcement.

Self-Defense Capabilities

For self-defense, the .40 S&W excels due to its potent combination of stopping power and a larger magazine capacity compared to larger calibers. Civilians and off-duty officers often select pistols chambered in .40 S&W for their defensive needs.

Recoil Management: The recoil of the .40 S&W is stout yet manageable in compact and full-sized pistols, allowing users to accurately place follow-up shots when necessary.

JHP Ammunition: The cartridge's performance is further enhanced when loaded with jacketed hollow point (JHP) bullets, which are designed to expand upon impact, maximizing stopping power while minimizing over-penetration—a critical requirement in self-defense scenarios.

Market and Availability

The .40 S&W cartridge had seen widespread adoption within law enforcement agencies and among self-defense enthusiasts, which impacted its availability and choice in firearms and ammunition. This caliber has established a solid foothold in the market with options for various firearms and a diverse selection of ammunition suited to different applications.

Popular Firearms and Ammunition

Glock 22 and Sig Sauer handguns are prominent examples that chamber the .40 S&W, offering a robust platform for law enforcement and personal defense. The Glock 22, in particular, gained popularity due to its reliability and capacity to handle the more substantial recoil of the .40 cartridge. It features a specifically engineered recoil spring assembly that aids in absorbing the kick. In contrast, handguns designed for the less powerful 9mm round, such as the Glock 17, don't require as robust a recoil system.

  • Firearms Chambered in .40 S&W:
    • Glock 22
    • Sig Sauer P229
    • Smith & Wesson M&P40

Handguns chambered in .45 ACP, which offers a different ballistic profile and recoil experience, often get compared to .40 S&W firearms in consumer choices. The preference for one over the other frequently hinges on the user’s comfort with recoil and handgun size.

Ammunition Selection

The market provides a vast assortment of .40 S&W ammunition, ranging from full metal jacket (FMJ) practice rounds to hollow-point designs optimized for self-defense. Major manufacturers like Federal Premium, Speer Gold Dot, Hornady, and Black Hills offer loads engineered for consistent performance and controlled expansion.

  • Popular .40 S&W Ammunition Brands:
    • Speer Gold Dot: Known for reliable expansion and law enforcement use
    • Federal Premium: Offers a variety of loads for different applications
    • Hornady: Renowned for self-defense with their Critical Duty and Critical Defense lines
    • Buffalo Bore: Heavy-hitting options for those seeking maximum stopping power

The availability of .40 S&W ammunition commonly reflects its popularity, with personal defense rounds like the Speer Gold Dot being favored for their balance of power and manageable recoil. This wide selection caters to the diverse needs of shooters, ranging from personal defense to target practice. Despite fluctuations in the firearms industry, the .40 S&W maintains a steadiness in availability due to ongoing consumer and law enforcement demand.

Frequently Asked Questions

This section provides clear, succinct answers to common questions about the .40 S&W cartridge, including comparisons to the 9mm, usage scenarios, reasons for its decline in law enforcement, and considerations for self-defense.

What are the ballistic comparisons between the .40 S&W and 9mm cartridges?

The .40 S&W typically fires a heavier bullet than the 9mm, often leading to more energy and better performance in terms of stopping power. In contrast, the 9mm generally has higher magazine capacity and lower recoil, which can improve shot accuracy and speed for some shooters.

In what scenarios is the .40 S&W caliber most effectively used?

The .40 S&W is effective in law enforcement and self-defense scenarios where its additional stopping power over the 9mm is desired. It strikes a balance between firepower and control, which can prove beneficial in close-quarters situations.

What has contributed to the decline in popularity of the .40 S&W?

Factors contributing to the .40 S&W's decline in popularity include the increased wear on firearms due to its high-pressure nature and the advancement in 9mm bullet technology, which offers similar performance with less recoil and higher capacity.

For what reasons did law enforcement agencies transition away from .40 S&W?

Many law enforcement agencies transitioned away from the .40 S&W due to the cumulative advantages of modern 9mm ammunition, including lower recoil, higher magazine capacity, and improved bullet technology, which offers comparable stopping power and ballistics.

How does the recoil of a .40 S&W compare to that of other calibers?

The recoil of a .40 S&W is typically more pronounced than that of a 9mm but less than the recoil of larger calibers like the .45 ACP. Shooters find the .40 S&W recoil manageable, though it may be tougher for smaller-framed or less experienced shooters.

What are the considerations for choosing .40 S&W for self-defense purposes?

Choosing .40 S&W for self-defense involves weighing its stopping power against its sharper recoil and lower magazine capacity, relative to the 9mm. It may be preferred by those who can handle the recoil and prioritize the caliber's higher energy per round.

Back to blog