Toggle menu
(724) 366-6590
Tech Talk: Flat Hop Assembly Guide

Tech Talk: Flat Hop Assembly Guide

Posted by The Blog Squad on Mar 25, 2024

TECH

Tech Talk: Flat Hop Assembly Guide

BY Jay P+

calendar_today   MAR 6, 2024
In this article, we will provide you with a comprehensive guide on how to flat-hop your airsoft gun. We will take you through the entire process, step by step, from products you need to valuable tips. We will explain why we prefer flat hop compared to normal hop, and how you can achieve better performance with them. By the end of this article, you will have a clear understanding of how to flat hop, the products you need, and how to use them to ensure that your time and money are well spent.

What is a Flat Hop?

Flat hop is a type of hop up where the bucking is either modified or swapped to have a flat surface in combination with a flat nub instead of a rounded one. This mod involves shaving down the center portion of the hop-up bucking to create a flat surface for the BB to make contact. A flat hop nub is longer than a standard nub, which means that it imparts more hop over the length of the barrel, resulting in less hop required to create more distance. This modification improves the accuracy and range of airsoft guns by providing a more consistent and stable backspin on the BBs.

What We Like About It:

  • Ease of installation: Flat hop can be achieved with basic tools and skills

  • Cost-effectiveness: Flat hop is cheaper than other barrel system upgrades, as it only requires a new hop-up bucking and a flat or concave nub

  • Compatibility: Flat hop is compatible with most barrels and hop-up units, as it only modifies the bucking. 

Barrel assembly for Flat Hop Airsoft

What You Need to Get Started:

Before we get into the "how-to" here's everything you are going to need.


  • Hop-up buckings: These are the rubber sleeves that cover the barrel and have a bump inside that contacts the BBs. For flat hop, you need to cut off the bump inside the bucking to create a flat surface. Our preferred bucking is the Prometheus Purple as it provides us with the most consistent shots. We don't need to use a super hard bucking with a flat hop, so the Promi Purple is the perfect choice. Some of the popular hop-up buckings for flat hop are:

  • Hop-up nubs: These are the small pieces of rubber that push the bucking down when the hop-up is adjusted. For flat hop, you need to use a flat or concave nub that matches the flat bucking. The Namazu flat hop nub from Firefly is our preferred option due to its reliable performance. Some of the popular hop-up nubs for flat hop are:

  • Roller Bar (usually included with Nub)

    • Orga Nub

Tools You'll Need:


  • Pliers

  • Lube

  • Scissors, Knife or Rotary Tool

  • Recommended: Prowin hop up

Flat Hop Assembly Instructions:

Now that you have gained a deeper understanding of flat hops and have everything you need, it is time to begin the building process.
Airsoft Barrel Assembly

Step 1

Remove the hop up unit and the barrel from the airsoft gun. The hop up unit is the part that controls the amount of backspin applied to the BBs, and the barrel is the tube that guides the BBs out of the gun.

Bucking and Nub Airsoft Barrel Assembly

Step 2

Remove the bucking and the nub from the hop up unit. The bucking is a rubber sleeve that covers the barrel and has a bump inside that contacts the BBs. The nub is a small piece of rubber that pushes the bucking down when the hop up is adjusted


** If you have an Orga Barrel: Install the Orga flat hop adjuster on the hop up arm, ensuring it is aligned with the hop up window. The Orga flat hop adjuster is a specially designed nub with a flat surface that matches the flat bucking. The Orga flat hop adjuster replaces the original nub, providing more surface area and pressure to the bucking.

Sanding a Bucking

Step 3

Turn the bucking inside out with pliers and lube it. Cut or sand off the bump inside the bucking carefully using a razor blade. This creates a flat surface inside the bucking that will contact the BBs evenly. Do not use a knife or scissors; using them can cause issues. Our preferred method is using a sanding bit on a dremel or belt sander if one is available.
Install hop-up

Step 4

Install the flat nub into the hop up arm, ensuring it is aligned with the hop-up window. The flat nub is a specially designed piece of rubber with a flat surface that matches the flat bucking. The flat nub replaces the original nub, providing more surface area and pressure to the bucking.

Install hop-up and barrel

Step 5

Reinstall the bucking and the barrel into the hop up unit. Ensure the bucking is aligned properly with the barrel and the hop up unit. The bucking should have a small notch that fits into a groove on the barrel, and the hop up unit should have a window that exposes the bucking.


When re-inserting the barrel with the bucking on it, apply a small amount of silicone-based lube to allow it to insert easily. Make sure that the lips do not curl over as you insert it, which will cause a jam later.
Maxx Hop Up

Step 6

Reinstall the hop up unit and the barrel into the airsoft gun. Ensure the hop-up unit is firmly secured and the barrel aligned correctly with the gun. The hop up unit should have a small pin that fits into a hole on the gun, and the barrel should have a small notch that fits into a slot on the hop up unit.

Airsoft Test Shooting

Step 7

Test the flat hop by shooting some BBs and adjusting the hop up. The hop up is usually a dial or a lever that changes the pressure applied to the bucking. The flat hop should provide a more consistent and accurate trajectory for the BBs, allowing them to fly farther and straighter.

Final Thoughts

We hope this guide helped you understand the flat hop process. 


If you still have questions, feel free to reach out to us here or check out our YouTube video detailing the process. 


You can also have us build it for you. Check out our barrel builds here.

From the Blog