.40 S&W vs 9mm: Which Pistol Caliber Wins in 2026?
February 20, 2026 · AmmoBin.com
The .40 S&W was designed as a do-everything law-enforcement round, but the last decade saw most agencies — including the FBI — return to 9mm. Here is why, and which is right for you.
Recoil and capacity
.40 S&W has a sharper, snappier recoil than 9mm and holds fewer rounds per magazine. 9mm is easier to shoot fast and accurately, which is the main reason agencies shifted back to it — modern 9mm defensive ammo closed the terminal gap.
Terminal performance
.40 fires a heavier bullet with more energy on paper, but with modern bonded hollow points both achieve the FBI-spec 12–18 inches of penetration with reliable expansion. Real-world effectiveness is very close.
Cost and which to pick
9mm is cheaper and more available, making it better for high-volume practice. Pick .40 if you already own one or prefer the heavier bullet; pick 9mm for value, capacity, and control. Compare live prices for .40 S&W and 9mm.
Frequently asked questions
Why did the FBI go back to 9mm from .40?
Modern 9mm defensive ammo matched .40's terminal performance while offering less recoil, higher capacity, and lower cost — so 9mm became the better practical choice.
Is .40 S&W more powerful than 9mm?
.40 has more energy and a heavier bullet on paper, but with quality hollow points real-world performance is very close. 9mm wins on recoil, capacity, and price.
Compare live prices