PDI – 6.05 R-hop Steel Inner Barrel


The R-hop is the absolute best upgrade for any gun to achieve maximum accuracy, range, and consistency for your trajectory. The Prometheus barrel combined with the R-hop professionally made by Hop Systems will give you amazing results that will surpass anything you’ve seen before.

Products are custom made to order, please allow a minimum of 3 weeks for labor time and shipping. Your order can be canceled by customer request at any time before shipment. Please see our FAQ for more information.


Flat-hopped Hop up Chamber

Customize your own RHOP Drop-in kit. Add a Flat-hopped hop up chamber and the correct matching bucking with the R-hop barrel of your choice. All orders will come pre-assembled into a drop in r-hop kit.

Flat-hopped Bucking

A Flat-hopped bucking is required with the R-hop barrel. You can purchase one with your R-hop barrel, or combine it with the matching hop up chamber to make a Drop-in R-hop Kit.

Flat Nubs

Sorbo Flat nubs require hop up modification. Modify and Prometheus nubs are drop-in flat nubs that require no modification.

Barrel Lapping

Adds 2 weeks of labor time.

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About the R-hop barrel: The RHOP barrel is the best trajectory performance enhancement for any airsoft gun. It improves your accuracy, range, consistency, durability, and more. It also allows the effective and efficient use of heavier bbs. A perfectly installed r-hop is the best trajectory upgrade that will surpass all other systems. Hop Systems promises a perfectly installed r-hop that will give you the best shot consistency and trajectory straightness. With the R-hop, you will be able to hit your targets more often, reach farther, and effectively use heavier bbs.

About the Inner Barrel: PDI manufactures the highest grade quality steel inner barrels you can get on the market, and they are famous for it. They are made in Japan, The machining method for PDI Barrels is cold-hammer forging, which is the same process that real firearm barrels undergo.  This process creates the best consistency for your bore. The machining tolerance for the inner barrel is +0.002mm, which means they offer the highest quality tolerance in the entire airsoft industry for inner barrels. PDI Barrels also have the best lapped inner bore surface quality for steel barrels on the market at ~20 microns. The steel material used is SUS304 Stainless Steel, which is the highest quality steel used for inner barrels on the airsoft market. PDI Barrels are also the straightest barrels on the market thanks to their superior machining. PDI Barrels also undergo strict quality control. In conclusion, PDI sought to make the best possible steel barrel on the airsoft consumer market and succeeded.

Requirements: You will need a flat-hopped bucking and ideally a sorbo flat hop nub or m-nub to install with your r-hop barrel ( You can still use the stock soft nub with great performance if you can’t use a soft flat nub ). You can find both items in our product options. Any errors in modification and installation can negatively affect the performance of the r-hop; Therefore, professional installation is recommended. For performance assurance and to save you the time and hassle of modifying the parts yourself; You can purchase an R-hop Drop-in Kit, or send in your hop up parts to us for professional installation and modification. Using high-quality heavy bbs is ideal for performance; 0.25g is good, 0.30g and up would be perfect. The heavier the bb, the better your accuracy, consistency, and range will be.

  • Professionally installed and tested before shipment
  • Comes with an extensive instructional manual for the r-hop.
  • Lifetime warranty: covers manufacturing defect only.

Compatibility: For Airsoft AEGs

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