Thats a great tip @Cruise I did smooth off the spring but perhaps I should glue a washer or something inside the piston head to take the brunt of where the spring meets it.
A Drawing of the pistonhead mod would be awesome if you would track it down! I can see how the gearbox would be out under punishment, I was thinking of leaving the 3 cell lipo mod out (even though I am tempted ) it appears to make the gears work a lot harder/faster.
The barell mod is interesting, you mentioned going down to a 7.1 or 7. is that the internal diameter? I imagine it would be worth going to aluminium if doing this? Do you mean that you require hardened gels with this mod when you refer to “usable gel hardness”?