Hi guys, I’ve got a Hw97 which somebody has modified by milling slots in the piston bringing the weight of piston and v Mach seal to app 220 grams which going by posts on the bbs made by some very knowledgeable people is a good weight, the transfer port of the compression cylinder seems to be 4.2mm or so measured in not the best way but the best method I have available by inserting a drill bit, 4mm is lose, 4.5 won’t fit, is the tp diameter too large? and if so is there anyone amongst us who could sleeve it for me as it’s way beyond my capabilities, the spring has 29 coils and there is no preload on the back block also piston seal feels quite tight , set up like this the rifle is 7.5 ft/lbs and feels quite harsh, I would obviously pay the proper rate for this work…Thanks…Lewis…