Hop up

Any good airsoft replica is fitted with hop up. This clever mechanism is a chamber which forces an adjustable amount of backspin onto a BB when fired. When hop is correctly adjusted the BB will fly in a straight line for a long distance until it loses momentum and drops to the ground very quickly, rather than dropping in a constant arc over distance. Unlike a paintball marker you do not need to aim up and lob your shots onto your target, you can shoot straight and use the weapon sights (or even use a telescopic scope) to make accurate shots.