Hw90/fenman

[sarfarm]

They share a similar system but not the same. The HW90 has the ram design developed in conjunction with HW.
Theres a lot of components inside the fenman ram and less in the 90 ram. The 90 is also a bigger diameter piston I believe whereas my fenman was 27mm. I wrote a stripdown guide for a fenman a few years ago. Very different kettle of fish to the 90

Your stripdown of the Fenman was a great help when I rebuilt mine.
From my stripdown of both guns the system seems the same the overall construction differs and I believe the stroke is different.