Hop-Up Guide – Everything you need to know about your hop-up
The hop-up is one of the most important components in your airsoft gun. It decides how far and how accurately your rifle shoots – and a correctly adjusted hop-up is the difference between a BB that drops to the ground after 20 metres and one that flies steadily out to 50+ metres.
In this guide we cover everything from the basic principle to advanced upgrades such as flat hop, R-hop and ER-hop.
What is a hop-up and what does it do?
The hop-up consists of three parts: a hop-up chamber, a hop-up bucking and a hop-up nub. Together they are fitted around the inner barrel and put the backspin on the BB that makes it fly far and stable.
As the BB passes the bucking, the nub presses the bucking lightly down onto the BB and makes it spin backwards. This rotation – the Magnus effect – makes the BB lift and hold its height far longer than it otherwise would.
The ideal trajectory is a long, flat path with a slight rise at the end. If the BB climbs straight away, the hop-up is set too high. If it drops quickly to the ground, it is set too low.
Where is the hop-up?
AEG rifles: At the top of the magazine well, reached through the dust cover on the side – usually opened by pulling the charging handle.
Gas/GBB pistols: At the front of the magazine well. Pull the slide back to see it – the slide often has to be removed completely before adjusting.
How to adjust your hop-up
Adjust the hop-up by turning the chamber wheel a little at a time – the direction is usually marked on the chamber. Test after each adjustment and find the setting where the BB flies long and flat with a slight rise at the end.
If you adjust too much, the BB starts to climb quickly and loses range. If it is set far too high, the BB can get stuck in the chamber – stop shooting immediately if that happens, to avoid damaging the gun.
Troubleshooting – what if the hop-up doesn't work?
Inconsistent hop-up after adjusting: Most likely a damaged hop-up bucking that needs replacing. Reassembling it correctly takes experience.
No hop-up effect at all: The bucking is probably greasy and needs a thorough clean on the inside. The chamber and barrel have to come out.
Inaccurate shots despite a good trajectory: The barrel is dirty and needs a thorough clean – we recommend a proper cleaning kit.
Should you upgrade your hop-up chamber?
Hop-up chambers come in two types: the toothed-wheel type (older) and the rotary type (newer). The rotary type holds its setting better over time and is generally preferable.
If your rifle already comes with a rotary chamber, we recommend keeping it, as it is the best match for the rifle. If you still want to upgrade, Prowin and MAXX make the best chambers on the market.
Which hop-up bucking should you choose?
The most important parameter is the durometer (hardness rating) – the higher the number, the harder the bucking. The hardness has to match your muzzle velocity for the bucking to get the optimum grip on the BB. As a rule of thumb (measured with 0.20 g BBs):
| Velocity | Recommended hardness |
|---|---|
| 90–110 m/s | 50–60 degrees |
| 110–140 m/s | 60–70 degrees |
| 140+ m/s | 70+ degrees |
Our recommendations:
Krytac bucking + Maple Leaf nub is our preferred combination in the workshop. Around 60 degrees and ideal for most standard AEGs.
Green G&G bucking is a well-proven classic – good to have to hand, especially on game day. Their newer blue bucking is also recommended.
Maple Leaf bucking is known for its flat inner contact patch and accurate hardness ratings. Combined with their own nub it gives an excellent contact surface – especially for rifles shooting above 140 m/s.
Advanced hop-up solutions
If you are chasing the very best, there are three advanced solutions, all of which give a larger contact surface and more consistent results:
Flat hop Take your preferred bucking (we recommend green G&G), turn it inside out and carefully cut off the nub bump and the guide ridge. Sand the inside until it is completely smooth, turn it back and rotate it 90 degrees on the barrel. Combined with a Maple Leaf nub it gives a larger contact surface and good results.
R-hop A patch made from precisely shaped rubber tubing that fills the hop-up window in the inner barrel exactly. It must be made by an experienced technician. Combined with a flat-hop bucking and a Maple Leaf nub it gives excellent results – especially with heavy BBs in DMRs and bolt-action rifles.
ER-hop A further development of R-hop where the window in the inner barrel is machined wider for the best results. It gives the largest possible contact surface but may require a custom-made nub. The ultimate choice for DMR and bolt-action setups.
Need help?
Want your bucking replaced, your hop-up adjusted or an upgrade to R-hop? Our workshop in Aulum, Denmark can do it for you.
👉 Read about our workshop services 👉 See our range of hop-up parts and buckings
