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At an open outdoor airsoft field, range is everything.

When first getting into the hobby, it can feel almost unfair with how far some of your enemy’s rifles can shoot. Your BBs might be struggling to make it past 120ft, while the opposing force seems to be able to send their shots soaring across the map with ease. Have they simply spent more on their rifle than you? Are they using arcane sorcery to enchant their BBs with gravity defying magic?

Likely, the answer is a little more simple: Someone on the enemy team is using heavier BBs paired with a flat-hopped bucking. When it comes to airsoft guns, there are countless modifications to be made that can inch out a tad more performance out of your rifle. Some modifications are more complicated to perform, and some definitely have more of a genuine impact on performance than others. In the case of the “Flat Hop” modification, there likely isn’t a better bang for your buck upgrade out there. Being able to shoot farther should be on every airsoft player’s agenda. That’s why I recommend upgrading your airsoft gun with a Flat Hop to just about anyone willing to open their rifle and take a peek at the internal mechanisms.

You might be wondering, “Why is it even called a flat hop?”

Put on your nerd glasses dear reader, for we are about to dive headfirst into some physics!



The image above is a Flat Hop Nub. Keep its shape in mind.



This is an example of a stock standard nub. Some have a hole in the center, but the most important detail is their round cylindrical shape.

All airsoft guns, as the title of the hobby implies, are powered by pressurized air that propel a BB down range. Without a hopup unit, these BBs might only fly 40-50 feet before falling to the ground due to gravity. Before pressurized air blasts a BB through your airsoft gun’s inner barrel, the BB sits in a rubber chamber that both holds the BB in the barrel and applies downward force onto the BB with each shot. This downward force applies backspin to the BB, which then changes the projectile’s aerodynamics. Much like how a firearm’s rifling imparts spin on a bullet, this spin imparted on the BB helps each shot glide through the air significantly farther.

Not all airsoft guns apply this backspin in the same way, however. A good majority of AEG airsoft rifles make use of a basic hopup application system with a stock bucking and nub. Much like a finger pressing down, a rounded force makes contact with the top of each BB before each shot is fired. While this configuration won’t yield the greatest accuracy and range compared to other options, it is jam-resistant and works incredibly well with lighter BBs, making these setups a good factory default for brands looking to appeal to a wide range of players.

In the case of a flat-hop nub, a wider flat patch makes contact with the top of your BB. Instead of a finger pressing straight down on the BB, the flat nub lays an extended finger gently atop the BB, maximizing contact while making as little downward pressure as possible. A flat hop setup makes far more rubber contact with each BB launched through it, applying a high amount of backspin. As a result, the flat-hop performs poorly with lighter BBs, often applying far too much spin to them for stable flight. The flat hop instead succeeds brilliantly with heavier BBs (0.28g+), applying a high amount of backspin without pressing down too hard on the BB. Less downward force applied to your BB will result in a straighter, more stable flight pattern. That combined with a greater amount of stable backspin applied can result in substantially increased range and accuracy for your airsoft gun.

This, fellow airsofters, is how opponents outrange you.

How do I Flat-Hop my AEG?

First, you’re going to need the flat hop components themselves. My go-to pick would be the Modify Baton Ryusoku since it comes with the flat bucking and nub as a package. An alternatively great pick is the EMG Atlas, which conveniently comes with two flat hop ready buckings. You will have to source the flat nub separately for these ones however. If the nub is all you need, the Modify Baton Nub alone is what I recommend.

Next, you’ll need to access your hopup chamber and barrel assembly. Depending on your rifle platform, reaching this part can vary in difficulty. Most M4 platforms simply require you to remove the frontmost receiver pin, while AKs can often require the entire gearbox assembly to first be removed. If you’re new to opening an airsoft rifle, I recommend watching a respective disassembly of your rifle model before attempting this process.


Removed from your rifle, your hopup system should look something like this

Upon detaching the hopup unit itself from the barrel, you should be left with the hopup bucking attached to the inner barrel. Some hopup units are mounted on by clips, and others by screws. Ensure that your hopup is applying no pressure to the bucking while removing it!


This is a hopup bucking.

Remove the stock bucking from the barrel and carefully replace it with the Flat bucking. Ensure to line up the centering line on the bottom of the rubber with the slit in the inner barrel.

Once the bucking is properly set on the inner barrel, re-attach your hop up unit. From here, disassemble the portion of your hop up unit applying pressure to your bucking. For M4s, it’ll either be a set of gears or the adjustment wheel itself that’ll need to be removed. For AKs, it’ll typically just be unscrewing the hopup slider. Once removed, you should have fresh access to your basic nub. It may even still be stuck to your hopup arm due to grease. Remove the old nub and place the flat nub in accordingly. Reconstruct the hopup unit and you should be good to go!


A fully disassembled hopup unit

While this process is one of the easier airsoft modifications out there, there are still some pitfalls that can cause the modification to fail. We highly recommend professional installation if possible to ensure that everything is aligned and set perfectly (Check out our EPS Tech Services here on Evike.com!).

Here are some common issues that may arise when setting up a flat hop, as well as how to go about fixing them:

- Little to no Hopup Applied: Take out your inner barrel and look down it while adjusting the hop. Does the nub seem to be applying pressure to the bucking? If not, the flat nub may be stuck in the hopup unit itself. Disassemble, and realign. At worst, you may have to cut a section off of your nub for better fitment

- BBs Now Consistently Jam: First ensure that your hopup isn’t set to the max, as this can make it difficult for lower power AEGs to fire off the BB. In some instances, your bucking rubber may be too hard to ensure proper feeding. Use a softer bucking.

Once your flat hop is all set and done, take to the field with some 0.32g BBs and behold as your shots soar across the battlefield beautifully. Every inch of range can make the difference between a hit and a miss on the airsoft battlefield. With a flat hop properly installed, you can trust your primary weapon of choice to dominate the battlefield with ease. Instead of watching helplessly as your opponents pelt you with rounds from beyond your effective range, you can now revel in your long distance supremacy as you rise to become exactly what you’ve feared. For more tips and tricks on how to gain an advantage on the airsoft field, check out my other articles here on Evike.com!