Now that you have played a couple of games and grown comfortable with your replica and its capabilities, what is next? Do you move on to your next rifle or pistol, or do you move towards honing your performance? Sure, you can go for the faster trigger response or higher RPS, but ask any airsoft regular and they will agree: start with the accuracy system. This all includes the HOP UP CHAMBER, INNER BARREL, BUCKING, and NUB. Since this level of upgrade does not require cracking open a gearbox, about a half an hour of labor can yield a significant boost in precision and accuracy. For this article I will even include my recommendations in each field.

G&G Armament TR16 MBR 556WH

HOP UP CHAMBER

The hop up chamber houses all the components and is essential in tuning the adjustment and maintaining a tight seal. As discussed in the New User AEG article there are typical 2 styles of M4 hop ups: standard and rotary. Though both are serviceable, I prefer the rotary-style for its wider range of hop adjustment and consistency when dialed in. Hop up chambers can be purchased in plastic or metal, and while some prefer plastic as it reduces wear on the nozzle and for its lower cost, others prefer metal for its rigidity in providing a consistent seal and fit. Either is fine when upgrading and experimentation can help you decide on the one that works best for you.

Rotary Hop Up Chambers: G&G Armament Plastic (Left) & LayLax Prometheus Metal (Right)

INNER BARREL

In short, the inner barrel is the channel in which the BB accelerates and exits, ideally towards the target. With this said there are many aspects that can determine the performance of your replica. For example, the material will make a noticeable difference in overall precision. Typical stock barrels are constructed out of aluminum or brass, which have some surface inconsistencies. These imperfections can interact with the BB as it propels through the inner barrel, directly impacting its spin and velocity. Upgraded barrels are constructed from more durable materials such as stainless steel or carbon steel which also hold a polished surface better. Furthermore, these inner barrels are built with stricter tolerances that even consider the straightness of the barrel to provide a smooth path for the BB.

Inner Barrel Construction Materials: Brass or Stainless Steel

Another aspect to consider is inner barrel length. It is true the length of the inner barrel will change the output velocity (FPS) but it is important to understand that it will not inherently improve accuracy or precision. An increase in barrel length will provide more power behind the BB to help with range, but the quality of the system overall will provide precision. My go-to is a precision, polished stainless steel inner barrel, such as the one pictured above.

BUCKING and NUB

The bucking is the rubber sleeve installed between the inner barrel and hop up chamber. Airsoft replicas will typically have a bucking with a molded form on the inside. A cylindrical rubber “nub” then pushes on this shape to control the pressure on the BB which determines the level of hop. There are several variations of this concept that consider the concept of increasing the contact surface to provide increased hop potential. This allows a higher backspin, which improves overall range and accuracy. This increase also allows the player to utilize heavier weighted BBs that can cut through wind with little to no deviations in its flight path.

Hop Up Bucking and Nub: Standard (Left) & Flat Hop (Right)

“Flat hopping” is the term used when coupling a flat hop nub with a straight bore bucking. It eliminates the need for the molded inner surface of the bucking and uses the shape of the nub to create the ideal contact surface. Though flat hops are the systems I recommend, it is worth mentioning the concept of “R-Hop.” This method involves forming a rubber patch along the “window” of the inner barrel. There is more work involved that I could cover at this time, but we can look into it in a later edition.

CONCLUSION

This was just a taste of the possibilities that can take your Airsoft replica to the next level. There are additional techniques that you can use to further improve your accuracy and precision. Countless sources of tutorials online cover this topic, with some pushing the envelope with improving the bucking seal, polishing the inner barrel, and more. Be sure to check with your local player base for continued advice as well.

Airsoft is versatile in that you determine what you get out of it. Some want to push towards historical accuracy, while some want to create something all their own. Again, it is important to find out what works best for you and what you want out of your replica. Improving accuracy and precision is a universally agreed upon area, and why we covered it today. If you have recommendations for what we should cover next, send us a message and we will work to include it in a later article. Until then, good luck out there and remember to have fun with this sport we call Airsoft.