Blue Line

The rise and fall of the .40

November 29, 2021  By Dave Brown

The return to the 9mm Luger for police in Canada

April 11, 1986 was one of the darkest days in FBI history. Two Special Agents were killed and six more were wounded in a shootout with two violent and heavily armed murderers that would go on for almost five minutes. A total of 145 rounds were exchanged in what would become one of the most studied events in law enforcement history.

The shootout in Dade County, Florida was to become one of the biggest watershed events in the history of police firearms training in North America. It would eventually lead to the spawning of an entirely new cartridge designed specifically for law enforcement officers – the .40 S&W.

In its search for a more powerful cartridge with better penetrative capability and the ability to punch through doors and windshields, the FBI initially commissioned a new cartridge called the 10mm Auto. When it proved almost too powerful for many of their agents to handle and the handguns too large and unwieldy because of the length of the cartridge, Smith & Wesson, in partnership with Winchester Western ammunition, designed a shorter cartridge with reduced gunpowder and the same diameter (.40-inch) bullet. The shorter case could now be contained in the same frame size as the existing 9mm Luger (also known as the 9mm Parabellum or 9×19) designs, but would fire a slightly larger diameter bullet than the .355-inch 9mm bullet and at a higher velocity.

We also now have a better understanding that the gun is not always the solution to every problem. The gun is only the tool; the mind is the weapon.


The .40 S&W cartridge proved to be very popular with police agencies, and by 2007, was selected as the cartridge of choice by half the armed law enforcement agencies in Canada. But by 2018, the percentage of agencies in Canada who stayed with the .40 S&W had dropped to less than 20 per cent. Why did they move back to the 9mm Luger, which was the original problematic ammunition for the FBI semi-automatic pistols back in 1986?

The answer is simple. Agencies were finding that the cost of the .40 S&W in higher recoil, greater muzzle flash and accelerated wear on handguns just did not pay off in better downrange or terminal performance.

Some agencies also found that the internal design of the base of the .40 S&W shell casing was inherently weaker than the internal casing of the 9mm Luger cartridge. Both cartridges are similar chamber pressures, but when using reloaded casings already weakened by a previous firing, certain makes of handguns with a small unsupported area on the underside of the chamber could potentially burst through the casing, destroying the handgun and sometimes detonating the top round of the magazine through flame-cutting.

But even without these rare situations with reloaded ammunition in the .40 S&W and .45 Auto handguns (which became known as ‘kabooms’), the .40 S&W was just not much fun to shoot.

Meanwhile the 9mm bullet design was not standing still. With the right configuration, the modern police-issue bullet began to perform equally well in 9mm Luger chambering as the more-powerful .40 S&W cartridge in both scientific tests and real-world shootings.

Born under fire, the .40 S&W was the right cartridge for the time, replacing the horribly excessive 10mm Auto. But modern training recognizes that the gun as a tool is far more than just its cartridge. The 9mm Luger is just as effective, easier to train on and much easier on wear and tear of high-round-count pistols.

Will an April 11, 1986 ever happen again? Who knows? No officer wakes up and says, “Today, I use my firearm to save someone’s life.” We now have better weapons, better tactics, and better training than was available in 1986. Today, we have a better understanding of the physiological and psychological reactions of the human body under stress. We have a recognition that even the best training and the best firearm in the world is not going to instantly stop a goal-oriented individual intent on killing.

We know based on what happened in 1986, and subsequent studies, that there is no “magic bullet” or “one-shot stop” cartridge. Stopping a threat is directly related to shot placement and shot penetration, and the 9mm Luger design could do both.

We also now have a better understanding that the gun is not always the solution to every problem. The gun is only the tool; the mind is the weapon.

When it comes to defensive weapons, training advances with the science. And sometimes science tells us the cartridge that was only starting to be issued to police officers in 1986 actually works just as good as the newer design, and has the advantage of being easier to train on.

While the fact that the 9mm Luger is more comfortable to shoot and thus easier to train on, may seem irrelevant to some, we don’t train for extraordinary people to have extraordinary skills when they are caught in unusual circumstances. We train for the average person to stay alive and to help others stay alive in spite of those challenging situations.

Training is a lifelong commitment to safety and advancement of skills. Training should not be a chore.

After all, advanced skills are simply the basics, mastered. Japanese musician and philosopher Shinichi Suzuki once said, “Knowledge is not skill. Knowledge plus ten thousand times is skill.”

Dave Brown is Blue Line’s firearms and police vehicle contributor, as well as one of the Best Dressed Police Vehicle Awards judges. He is a tactical firearms trainer and consultant based in Winnipeg. He can be reached at

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