What Is Hop Up? An Airsoft BB Gun Guide

wha is hop up airsoft

Hop-up (or High Operation Power Up) is the back-spin put on airsoft BBs to increase their range via something called the Magnus Effect.

By applying backspin to a projectile, you get better range and better accuracy. In airsoft guns, this is usually implemented as a projection (called a bucking) into the path of the BB, on the top of the barrel.

The bucking momentarily hinders the top side of the BB, applying a backspin that can exceed 120,000 revolutions per minute. This is usually adjustable so that the effect can be tuned to suit the weight or speed of the BB and reach your specific needs in terms of range.

What is the Magnus Effect?

Better known as topspin, the Magnus Effect allows balls in motion to travel further through the air. When you fire a BB, there is a layer of non-moving air (the boundary layer) on its surface.

When a BB spins, this layer gets thrown off at an angle. Newton’s laws state that in order for air to be thrown in one direction, the ball has to move in the opposite direction.

According to the Magnus Effect, the rotating BB would throw air downward and to the rear, thus giving lift. The boundary layers on the top and bottom separate unevenly, creating a wake that is lower than the middle of the BB, appearing like a comet’s tail pointing down.

It’s commonly seen on golf courses. The curved path of a golf ball known as slice or hook is due largely to the ball’s spinning motion and the Magnus effect, causing a horizontal force that moves the ball from a straight line in its trajectory.

airsoft magnus effect
What Is Hop Up? An Airsoft BB Gun Guide

Backspin on a golf ball causes a vertical force that counteracts the force of gravity slightly, and enables the ball to remain airborne a little longer than it would were the ball not spinning: this allows the ball to travel farther than a ball not spinning about its horizontal axis.

Hop Up System On An Airsoft Gun Explained!

The hop-up system on an airsoft gun is a mechanical device that applies backspin to the BB as it exits the barrel. The amount of backspin can be adjusted, which in turn adjusts the range and accuracy of the gun

The hop-up system is usually located inside the gun’s body, near the magazine well. It consists of a small rubber nub (called a bucking) that protrudes into the path of the BB as it exits the barrel

When the BB hits the bucking, it momentarily hinders the top side of the BB, applying a backspin. The amount of backspin can be adjusted by changing the position of the bucking.

airsoft hop up system
What Is Hop Up? An Airsoft BB Gun Guide

The hop-up system is a key component in an airsoft gun, and can be the difference between a gun that shoots straight and one that doesn’t. If you’re having trouble with your airsoft gun shooting straight, it’s likely due to the hop-up not being adjusted properly.

To adjust the hop-up on your airsoft gun, start by finding the hop-up adjustment knob. This is usually located near the magazine well, and may be hidden behind a small access panel.

Once you’ve found the adjustment knob, turn it clockwise to increase the amount of backspin (and thus, range), or counterclockwise to decrease it. Experiment until you find a setting that works for you.

Keep in mind that the hop-up system is a delicate mechanism, and can be easily damaged if not handled properly. Be careful not to apply too much force when adjusting the hop-up, as this can strip the gears or break the bucking.

If you’re not sure how to adjust the hop-up on your gun, consult the manual or contact the manufacturer.

Setting Up Your Airsoft Gun Hop Up Video Guide

YouTube video

How to Adjust Your Airsoft Gun Hop Up

Here is a general step-by-step guide on how to adjust your hop up. Remember, every gun is different, so this is a general guide

Step 1.

Pull back your charging handle to reveal your rifle’s hop unit and locate the hop adjuster dial

Step 2

Turn the dial clockwise to increase hop up. Turn the dial anti-clockwise to decrease hop up.

Step 3

Test your airsoft gun to make sure you fire straight. Adjust as appropriate and test again until you’re firing true. Thanks to a hop up, your airsoft gun works more efficiently, firing your BBs further and faster. And the faster they fire, the more accurate they are because they’re less likely to be thrown off by wind.

So there you have it!

Airsoft – it doesn’t just teach you the subtle art of not getting shot in the face. Sometimes you learn aerodynamics too. To make sure you’ve calibrated your airsoft gun properly, why not test your FPS on our calculator?


About Laurence

Laurence is a keen airsoft player and has been the owner of SoCom Tactical for over 10 years. He’s played airsoft all over the country solo and as part of teams and is an expert on all things airsoft, like tactics, airsoft guns and gameplay equipment. As one of the UK’s leading airsoft suppliers and retailers, Laurence is the go-to source for airsoft knowledge.