Hi Raj Thanks for reply. I did wind in valve screw to 10mm it was originally 8mm. Had another chrono this evening. Best I got was 760fps with one low power shot. Did wind hammer Spring right in. This oddly dropped the power so wound back out a couple of turns to get it back to consistent 750-760fps....

Hi have a s200 .177. Have wound out transfer port screw. Adjusted hammer spring and getting at best 11lb/ft. Have a bit more adjustment but it's making cocking obviously harder. Tried winding it in more and power slightly dropped oddly. Spring is genuine and new too. Not sure we're to go from here. ...