When writing my earlier post the idea of filling the cylinder ahead of the piston with water crossed my mind too. I thought if I suggested it someone might say'ok, you first' & I wouldn't fancy trying to dry out intrrnals of a springer, even a clunker of a springer. Still as a theoretical model it would be interesting if the weight of the fluid could somehow be factored out & the empirical perfomance evaluated with changes being introduced step by step so the effects of them could be measured. It would take out any varriability arising from the clmpressability of the air. But how it would translate into the real world is anyones guess so I think the advice that life is too short & its probably better to just roll up your sleeves & get cracking ks good advice.

It will be interesting to see any results from those that have carried them out.......standard rifle v port diameter, differant stroke v port diameter or variability with port volume etc. Its a big topic........but very interesting.