PGC Hop Up Kit for Western Arms (WA) M4 Series. ONLY suitable for AEG inner barrels.
Make no mistake: This is not just a reinforced replacement part for the original ABS plastic hop-up chamber, but a rather cunning innovation for better performance as well! Constructed from high impact polymer, this hop-up chamber allows you to use regular AEG inner barrels in your Western Arms (WA) M4A1 series GBB rifles for a better choice of length, material and nominal bore of the barrel.
Other virtues of this kit includes an adjustment dial that rotates just shy of 360° for a wide range of adjustment, and it is similar in design to the acclaimed SIG and G36 series hop-ups of AEGs. The swinging arm has two pressure points for a more consistent spin and better centering of the BB in the chamber. Hop-up rubber included.
Revision update: When installing, please do not insert the pin into the hop-up rubber, opposite to what is shown in the included diagram.
Highly recommended by RedWolf!
Pictures below shows the Correct Installaion of the Hop Up Kit.