The velocity of a bullet when fired from a gun describes the total distance the bullet traveled and how long it took to get there. A number of things affect a bullet's velocity including wind resistance, the size of the bullet and the type of gun. However, no matter what type of gun or bullet you're using you can find the velocity using a standard mathematical equation.
Things You'll Need
 Stopwatch
 Tape measure

Catalog the amount of time it takes the bullet to leave the gun when fired to the point where it reaches its destination. For example, if you're at a firing range you would use a stopwatch to find the time, in seconds, that it takes the bullet to leave the gun and hit the target.

Find the distance, in feet, between your two points in Step 1. For example, if you're at a firing range you would measure the length between the point where the gun was fired and the target where the bullet eventually ended up. Divide your feet calculation by 3.3 to convert it from feet to meters, as 1 meter is equal to 3.3 feet.

Divide the total distance, in meters, that the bullet traveled by the total number of seconds it took for the bullet to move from "point A" to "point B." For example, if you are at a firing range and the bullet moved 25 meters in two seconds, 25 divided by 2 equals 12.5 meters per second. The velocity of the bullet would be 12.5 meters per second.