40 Smith & Wesson Ammunition | .40 Cal Ammo for Self-Defense and Law Enforcement

40 S&W Pistol Ammunition was developed as an unstoppable cartridge for law enforcement, and it is an excellent choice for concealed carry owners who need the best handgun ammunition for self-defense. Also known as 40 S&W ammo, .40 ammo, and 40 cal ammo, they’re all the same thing and come in a variety of 40 cal bullets depending on your needs. We carry a wide variety of .40 caliber ammo including Full Metal Jacket (FMJ) rounds for range training and Hollow Point (HP) cartridges for home defense. If you’re unsure which type of ammo is best for your needs, check out our helpful Ammo How-To Guides that dive into various reloading terms and discuss how to shop online for ammunition.image

Stock up on top-shelf 40 Smith & Wesson pistol ammo right here at OpticsPlanet, including money-saving 40 cal bulk ammo! We carry the most popular ammunition brands including Hornady, Winchester, and Federal Premium. Since most orders over $49.00 get FREE SHIPPING!, there’s never been a better time to shop online with us!

Other categories you might be interested in are 9mm Luger Ammunition, 410 Gauge Ammo, 44 Magnum Ammunition, 45 ACP Ammunition, 45 Colt Ammunition.

The .40 S&W (10×22mm Smith & Wesson) is a rimless pistol cartridge developed jointly by major American firearms manufacturers Smith & Wesson and Winchester. The .40 S&W was developed from the ground up as a law enforcement cartridge designed to duplicate performance of the Federal Bureau of Investigation’s reduced-velocity 10mm Auto cartridge which could be retrofitted into medium-frame (9mm size) automatic handguns.


The 9mm has a bullet diameter of 9.01mm (0.355 in), a neck diameter of 9.65mm, a base diameter of 9.93 mm, a rim diameter of 9.96mm and a rim thickness of 0.90 mm.

The .40 has a bullet diameter of 10.2mm (.400 in), a neck diameter of 10.7mm, a shoulder diameter of 10.7 mm, a base diameter of 10.8mm, a rim diameter of 10.8mm and a rim thickness of 1.4mm.

Magazine capacity

Due to the smaller size of the bullet, 9mm guns typically have a higher magazine capacity than a .40, although the specifics vary depending on the type of gun. For example, the Beretta 92 gun holds 15 rounds of 9mm bullets, while the Beretta 96 holds 12 rounds of .40 bullets. Similarly, the Glock 17 holds a standard 17 rounds of 9mm bullets, while the Glock 22 holds a standard 15 rounds of .40 bullets.

.40 S&W Pros and Cons

The .40 round is fun to shoot overall, but there have been stories and some evidence of malfunctions happening with over-pressurization. The ammo can come pretty cheap, it is accessible, and it produces a more mild recoil than other 10mm diameter rounds. However, remember that it was designed as a service cartridge. It doesn’t have too many uses besides that. It is no good as a hunting round, and it can prove to be too expensive for target practice.

Since it is a heavier round, it won’t fly as fast as, say, a 9mm. But again, for self-defense purposes it works just fine. It has enough stopping power and is fast enough to reach any target within considerable distance. The effective range of a .40 S&W is more than enough for most armed confrontations. It comes down to the shooter’s skill.