I am currently tuning a HW85
From memory years ago when I last did this, one secret was to open up the transfer port slightly to I think 1/8th inch, the idea was to reduce recoil but not increase power.
Also the transfer port on my HW85 is at an angle upwards, which I do not remember from previous guns.

Any help or coments would be welcome.

Out of interest I await a Venom kit with new spring , guides etc