Why is the 9mm Replacing the 40 S&W?

hornady-9A lot of people believe that the bigger the round, the more stopping power it has. Which is why the 40 S&W round was given precedence over smaller caliber weapons in many law enforcement agencies, including the FBI. Now, while theoretically true about a bigger bullet bringing more stopping power when shooting at a target, there are many other factors involved than just stopping power alone, and that’s why the 9mm is once again gaining popularity as the caliber of choice.

In fact, after extensive testing, the FBI is changing their firearms back to the 9mm from the 40 S&W, which had become the most popular weapon on the force. Here are some of the reasons why.

Technical Specs — A 40 S&W is about a size 10mm bullet, which is 1mm larger than a 9mm. Velocity is around 1400 FPS for each, and depending upon the ammo used, expansion is between roughly .4 to .7 inches. As you can see, when broken down in purely technical terms, there isn’t much difference between the two. This is an important factor to remember.

Lighter Weight — The smaller caliber 9mm pistol is lighter in weight, which inherently makes it easier to bring into action. This may not matter to a larger individual, but for smaller individuals, getting ready to shoot in the heat of the moment, may cost a bit more time to steady and aim, and that could be the difference between life or death.

More Ammo — The mag on a 9mm generally carries more ammo than a 40 S&W. Those few extra rounds in the clip, when needed, allows the shooter to put more shots into the target without reloading.

Shootability — It has been found that if you can shoot a 40 S&W well, you can shoot a 9mm better. The lighter weight and less recoil of the 9mm make keeping it on target far easier than the 40.

Technological Developments — Bullet and propellant design are making the 9mm more formidable than ever before. As seen in the technical specs, it hits just about as hard as the 40 S&W, and even the expansion rate on a smaller bullet is very similar. These specifications were not possible only a few years before, and are one of the main reasons the FBI is switching back to the 9mm..

Less Cost — A high-quality smaller gun that shoots a smaller bullet always costs less than a high-quality larger gun that shoots a larger bullet, especially when there is a bulk purchase of the weapon. Now, if the performance was radically different, the extra cost would be worth it. But in these modern days of working on a budget, and with no appreciable difference in overall performance, the 9mm is just a better economic deal.

Longer Lasting — One thing that no one can take away from a 9mm is how long they last. This caliber, on the whole, is one of the most durable weapons ever designed. Of course the 9mm bullet has been around for over 100 years, so you’d figure by now that they would have gotten it right, and they have. Modern 9’s have the capability of firing over 100,000 rounds over their service life. That’s tough to beat for any caliber firearm.

Reliability — 9mm pistols are proven to jam less, foul less and work well with either practice or duty ammo. All of these factors make the 9 a better pistol to use when under stress and when you absolutely need a pistol to work, no matter what.

Shot Placement — No matter what caliber is used, shot placement is the key. It doesn’t matter if you use a 22 or a 45, if you don’t hit a critical area, they won’t be stopped. This factor, right here, is why the 9mm is gaining in popularity once again.

The FBI’s exact reasons for switching

The FBI did extensive testing to reach these conclusions:

  • 9mm Luger now offers select projectiles which are, under identical testing conditions, I outperforming most of the premium line .40 S&W and .45 Auto projectiles tested by the FBI
  • 9mm Luger offers higher magazine capacities, less recoil, lower cost (both in ammunition and wear on the weapons) and higher functional reliability rates (in FBI weapons)
  • The majority of FBI shooters are both FASTER in shot strings fired and more ACCURATE with shooting a 9mm Luger vs shooting a .40 S&W (similar sized weapons)



Newer bullet designs make the 9mm as effective as a .40 S&W. People can shoot 9mms faster and more accurately than a .40 S&W and the gun is more accurate as well.

Obviously, no one ever wants to get into a situation where they have to pull a gun, much less use it. But if you are in the business of law enforcement, particularly with the results found by testing from the FBI, the 9mm is a better overall choice than the S&W 40mm. That doesn’t mean the S&W is a bad weapon, it still has it’s place, but in a life or death situation, even the FBI realizes that the 9mm is a life saver, and you can’t ask for better than that.

If you are looking for .40 S&W or 9mm ammo be sure to visit us on the web at Spillway Sportsman.

You may also like...

1 Response

  1. June 23, 2016

    […] Bullet: The round used to stop an intruder or attacker must be adequate to stop the bad guy. A .380 is a small bullet but we don’t know anybody who wants to get hit with one. This round is really what we consider the minimum for a self defense handgun. A lot of people want to discuss stopping power of a round, but far more important is shot placement. A hit with a .380 is much better than a miss with a .45. The .45, .357, .40 and 9mm are all big rounds which are very popular. 9mm guns are (generally) very reliable, the FBI uses them, and you can read about why the 9mm is so popular here. […]

Leave a Reply

Your email address will not be published. Required fields are marked *