Kinetic energy is the energy that is in the pellet while it moves, and it is transferred to its target upon impact. One joule of energy will be transferred by a 0.20 g BB traveling at 100 metres per second (330 ft/s). A typical set of limits on guns might be 100 m/s (330 ft/s) for CQB, 125 m/s (410 ft/s) for outdoors, and 175 m/s (570 ft/s) for bolt action sniper rifles, all measured with a 0.20 g BB. The amount of kinetic energy depends on the weight of the BB and how fast the gun can propel it. Certain places play “no velocity limit” games. In California the average limit for CQB is 350 and below. On most fields in America the limit for AEG (Austomatic Electric Gun) guns is usually in the 400ft/s range. For snipers the range can be any where from 400 to 550ft/s. Guns have these high velocities to go farther at a much more accurate rate, but fire rate is compromised unless a smaller spring is added (preferably 110%). Furthermore, the lower velocity means that the BB will glide more, which is a good thing for indoor skirmishes, but outside the wind usually catches hold of it and spirals it out of its course.

In the United Kingdom, Ireland, and Italy, the energy limit for Airsoft guns is one joule (100 m/s with a 0.20 g, 6 mm BB) regardless of the type of game play. Some UK sites allow semi-automatic-only weapons up to 400FPS and bolt action rifles up to 500FPS. Northern Ireland has a maximum velocity of 328FPS with 0.2 gram BB without regard to the type of weapon.

Most Airsoft guns are capable of shooting from 50 m/s (160 ft/s) to 125 m/s (410 ft/s), although it is also possible to purchase upgraded internals for some Airsoft guns that will enable up to 210 m/s (690 ft/s) projectile velocities.

A hop-up unit, if present, puts a backspin on the BB to generate lift and give it a greater effective range. The range of any Airsoft gun depends on both the muzzle velocity and the amount of hop applied. Airsoft guns can have a range of 75 metres (246 ft) or more with the right combination of power, barrel, and ammunition when combined with a good hop-up unit. A good hop-up unit can sometimes double the range.