Few handgun cartridges have had a rise – and a perceived fall – as dramatic as the .40 S&W. Once the dominant law enforcement round in the United States, it has since ceded ground to 9mm in many agencies. Yet despite shifting trends, the .40 S&W continues to hold a firm place in the firearms world. Its staying power comes down to performance, versatility, and a loyal user base that still values what it was designed to deliver.
.40 S&W Origins: Born from a Need for Balance
The .40 S&W traces its roots to the aftermath of the 1986 FBI Miami shootout, a pivotal event that reshaped law enforcement thinking about handgun effectiveness. The FBI concluded that deeper penetration and greater stopping power were needed than what standard 9mm loads of the time offered.
Initially, the Bureau turned to the more powerful 10mm Auto, but it quickly became clear that the full-power 10mm was difficult for many agents to control and required large-framed pistols, making them more difficult to conceal. This led to a reduced power 10mm load, often called the “10mm Lite.”
Recognizing an opportunity, Smith & Wesson partnered with Winchester to shorten the 10mm case and create a cartridge that could fit into 9mm-sized handguns. The result, introduced in 1990, was the .40 S&W.
Rapid Adoption: Law Enforcement’s Favorite
Throughout the 1990s and early 2000s, the .40 S&W became the dominant law enforcement cartridge in the U.S.
Many agencies appreciated its balance:
- More energy and larger bullet diameter than 9mm
- Higher capacity and easier handling than .45 ACP
- Manageable recoil compared to full-power 10mm
The .40 S&W was perceived to be something of the “Goldilocks” of handgun cartridges being not too punishing to shoot and more powerful than the 9mm – just right.
Large agencies, including the Federal Bureau of Investigation for a period, standardized on .40 S&W. It became synonymous with duty carry, and nearly every major handgun manufacturer produced models chambered for it.
The Shift Back to 9mm
By the 2010s, improvements in bullet design (especially bonded and expanding projectiles) significantly enhanced 9mm performance. At the same time, agencies began prioritizing:
- Higher magazine capacity
- Faster follow-up shots
- Reduced recoil for training consistency
- Lower ammunition costs
As a result, many departments, including the FBI, returned to 9mm. This led some to prematurely declare the .40 S&W “obsolete.”
.40 S&W Ammo
As many agencies rotated away from the .40 S&W to the 9mm, they put thousands of surplus .40 caliber pistols into the civilian market. Many consumers snapped up .40 caliber pistols made by Glock, Smith & Wesson, Sig Sauer, and other quality brands. Ironically, the so-called “decline” of the .40 S&W in law enforcement circles created a large civilian market for .40 S&W ammunition. Today, you can find .40 S&W ammunition on the shelves of nearly every big box sporting goods store and most local gun shops.
Who Still Uses .40 S&W?
Despite the shift, the .40 S&W remains widely used by several market segments including:
Law Enforcement (Selective Use). Some agencies and officers continue to carry .40-caliber pistols, especially those who prefer its recoil impulse and terminal performance.
Civilian Self-Defense. Concealed carriers and home defenders who want more perceived stopping power than 9mm, but less bulk than .45 ACP, often choose .40.
Firearms Enthusiasts. Many experienced shooters appreciate the cartridge for its “middle ground” characteristics and continue to stock it.
Security and Private Contractors. Certain private security roles still favor .40 S&W due to legacy equipment and training.
Why the .40 S&W Still Has a Place
Even in a 9mm-dominated era, the .40 S&W persists for several reasons:
- Proven Track Record. Decades of real-world use have built confidence in its effectiveness.
- Ballistic Middle Ground. It sits squarely between 9mm and .45 ACP with a heavier bullet than the 9mm and higher velocity than the .45 ACP.
- Because of its past popularity, firearms and ammunition remain widely available, and often at attractive prices.
- Ammunition Options. Major ammunition manufacturers continue to make a wide variety of ammo choices, from target rounds to those suitable for self-defense.
- Ammo Market Cycles. During shortages, .40 S&W is sometimes easier to find than more popular calibers.
For these and other reasons, quality brands continue to make new pistols chambered in .40 S&W, including Smith & Wesson, of course, as well as HK, Glock, Beretta and others. In many cases, a used .40 S&W law enforcement trade-in can offer a budget-conscious alternative to purchasing a new version of the same model in 9mm.
Comparing .40 S&W to 10mm and .45 ACP
The table below summarizes the primary differences between the venerable .40 S&W and two other large bore, popular pistol cartridges – the 10mm and .45 ACP.
The Real Story: Not Dead, Just Repositioned
The .40 S&W hasn’t disappeared; it’s simply no longer the default choice of law enforcement agencies. Its role has shifted from “standard issue” to “specialized preference.”
Shooters who value:
- A step up in power from 9mm
- Manageable recoil compared to 10mm
- Greater capacity than .45 ACP
…will continue to find the .40 S&W a compelling option.
Final Thoughts
Trends in firearms often move in cycles, driven by technology, training philosophy, and economics. The .40 S&W rose to prominence by solving a real problem, and it still solves that problem today.
It may no longer dominate duty holsters, but it remains a capable, relevant cartridge that has earned its place in concealed carry and home defense roles.
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I’d like to see an article on the .357 Sig.
Reyn,
Funny you should write that; I always wanted that caliber and a gun to shoot that round. I am looking for a Glock in that caliber right now. I promise to write one for you.