AIRSOFT 101: HOP-UP

Airsoft 101 : Hop-Up

Hop-up refers to a device inside modern airsoft guns which places a backspin on the BB as it is fired.

This backspin is controllable through the hop-ups use of a rubber ‘nub’ which is lowered into the firing chamber. As the BB leaves the gun, it touches this rubber and is given a variety of backspins.



AEG Maintenance Guide

The following guide contains simple rules that AEG owners should keep in mind for best results in a long lifespan of the replica. Please note that your manufacturer may have additional specific guidelines for the product you have, be mindful of the manuals they include. This guide is only meant as a broad supplement.

1. DO NOT dry fire your AEG needlessly. If there's no object loaded in your chamber to create resistance when fired, your piston will hit with the maximum force against the front half of your gearbox, that's how you crack gearboxes. Sometimes, dry fire is inevitable when you run out of ammo, but do your best to limit this possibility. Listen for the sound difference your AEG makes when it's empty and change up that magazine as quickly as possible.

2. Decompress the spring. If you fire your AEG on full auto, it's possible that your piston may stop in a position that leaves the spring compressed. This can cause wear on the spring and weaken the firepower of your AEG at a much quicker pace. Fire the AEG on semi-auto 2-3 times after use to decompress the spring.

3. Never reuse BBs! Dirt, dust, and grime can cause wear on your hopup and feeding mechanisms. Always use new BBs. If you want to reuse them so bad, save them for your cheapo spring guns but DO NOT use them again in your AEG.

4. Always shoot with a full battery. A lower rate of fire can cause the AEG to cycle incorrectly and even throw your gears out of time. When you hear your battery starting to give, immediately charge it or change to a fully charged battery. DO NOT continue to fire it until the battery is completely dead.

5. Discharge your battery before charging. It's always best practice to discharge your battery fully before charging, this will ensure you get a full charge and your battery won't retain memory. We recommend buying a charger with a discharge function for this reason.

6. Avoid contact with Water/Dirt/Sand. In excess, water, dirt, and sand can all damage your replica. Obviously this is a very active outdoor hobby and we do get dirty and wet, but try your best to keep your AEG internals and inner barrel out of harm's way.

7. Wipe down your AEG after use in the rain. Standing water droplets on some AEG parts can cause oxidization. It's best to wipe down your AEG with a towel or a cloth thoroughly after use on a rainy day.

8. Periodically swab your barrel and lube moving parts. Be warned that some lubes, even those used on your real firearms, can damage AEG internals. You need to use 100% pure silicon spray when swabbing your inner barrel. Be sure to turn your hopup down all the way before doing barrel maintenance. Use the cleaning tool that came with your AEG and insert a piece of clean fabric (like a cotton gun cleaning patch) into the small notch at the end. Apply a small amount of silicon spray to the cotton patch and run the cleaning rod down the length of the barrel, slowly pull it back out while twisting. Repeat the process until the cotton/cloth comes out clean. Most cleaning rods have a mark that indicates how far you can insert the cleaning tool without contacting the hopup, do not exceed this mark! You may also want to apply silicon spray to some of the metal on metal external moving parts, if your model has any. You may also want to apply a single drop of silicon into the feed port, run about 100 rounds through it after you do this to clear any excess silicon. (The first shots may be erratic).

9. For those upgrading gearboxes. DO NOT use silicon spray as a lube, it will evaporate at some point and you will not have lubrication at all. Use either a silicon grease or white lithium grease. We don't recommend that you do your own gearbox upgrades unless you consider yourself a mechanically minded person who might actually enjoy troubleshooting the process of putting it all back together in working order.

10. Avoid using external parts needlessly. Some external moving parts are just for looks and serve no purpose for the function of the AEG itself. It's best that you don't tamper with these too much, in some cases they'll wear out or break easily.


So how does it exactly work?

Bernoulli's principle is a physical law that says that if a pellet is given a backspin an overpressure is formed under the bullet and an under pressure is formed on the top of the bullet. These pressures affect the bullet as on an airplanes wings a lift is formed. The bullet is sucked upwards. If the force caused by the backspin is equal to the effect of gravitation the bullet will fall slower and have a flatter trajectory, which gives the pellet longer range.





Here are some things to keep in mind.

- It is best to store a gun with the hop-up off (the starting position.)The rubber may become conditioned otherwise. Either reducing the effectiveness or giving a permanent hop-up effect.

- Once engaged the hop-up will slightly slow a BB: 1-5fps, fully engaged up to 6-10fps.

- Always chrono with the hop-up off.

- Upgrading an AEG with a spring to shoot faster, may require a upgrade to the hop-up. If a BB moves too quickly through the hop-up unit, it may not acquire the desirable backspin. To compensate there are a number of aftermarket parts, usually just larger pieces of rubber, which are pushed farther into the barrel.

- A special caution to CA m249 owners. The hop up on these new guns is dreadfully strong and has been known to damage internals if engaged too much. Aftermarket parts (such as a new piston) will reduce this risk.