Muzzle velocity is simply the speed of the bullet as it leaves the barrel.
It’s usually measured in feet per second, or fps, and it plays a major role in the bullet’s trajectory. Higher muzzle velocity generally means the bullet gets to the target sooner and drops less over a given distance, but velocity alone doesn’t tell you everything about how a bullet will perform.
The bullet’s ballistic coefficient, drag, and the atmosphere all affect how quickly it slows after leaving the muzzle.
For the best ballistic predictions, use the rifle’s actual muzzle velocity, not just the number printed on the ammunition box. Factory velocity numbers are usually produced in test barrels and may not match your rifle, especially if your barrel length is different.
A chronograph is the easiest way to measure actual muzzle velocity. Once you have that number, you can use it in a ballistic calculator to build a much more accurate trajectory for your rifle.
If you want to keep going, read our Shorts on What Is Ballistic Coefficient?, What Is Point-Blank Range?, and How Far Should I Zero My Hunting Rifle?