Forty vs. Nine Millimeter: Understanding the Differences in Size
Cartridge Dimensions: A Head-to-Head Comparison Bullet Diameter The most obvious, and perhaps the most often cited, difference is the diameter of the bullet itself. The .40 S&W has a larger bullet diameter. Specifically, a forty caliber bullet measures roughly point four zero zero inches, giving it its name. On the other hand, the nine-millimeter bullet … Read more