The 9mm is the single most popular handgun cartridge in the world. There are many reasons to love the 9mm round, but the most common are price, availability, accuracy, useability, capacity, and concealability. It's a workhorse caliber that fits any budget or taste — it's quite literally the caliber for anyone. From first-time shooters to the FBI, from U.S. military special operations to soccer moms who conceal carry, it’s as utilitarian of a round and caliber as any could possibly be. One of the main attributes that contributed to the success of 9mm ammo, other than accuracy, is that it can hold tremendous capacity in magazines.  The 9mm cartridge allows a large magazine to fit into a small gun while still supporting performance that outshines competitors. Over time the round was forced to compete with other calibers, and it became the standard-bearer. When it comes to hitting the target, the 9mm round has proven to be consistent. 9mm has a flat trajectory, which helps it stay on target better, and while it's rated to 50 yards, anecdotal evidence demonstrates that you can hit targets considerably farther out (some targets located at 100 yards or more away. While you might never have the need to attempt such a feat, knowing that the round can travel that distance and hit what you were aiming at is a huge mark in the plus column. This also makes it easier to increase your own performance in target shooting at close ranges and makes for better efficiency in a self-defense situation.