The idea is that in some guns (maybe not all), the self-regulation of the valve (ie increase in lift) as the air pressure reduces is too great.... I'm sure you have heard PCPs get louder as the shot string progresses?.... That is because the efficiency is less in the latter part of the string.... With this mod the idea is to "knock the top off" the bell curve, flattening it, and then retaining some of that air for later shots, which use progressively less volume of air, but at a slightly higher pressure, thereby producing more shots overall.... I've NEVER tried it, this experiment is a first for me.... however, the success that this method of tuning has produced in the MROds and PRods is very good....

It also makes the tuning process easier overall, as once the ideal hammer spring preload has been found for the fill pressure, backing out the striker reduces the lift and hence reduces the power.... Again, I've never tried it, but the claims are that strings detuned in this way are significantly flatter, and hence longer, than those achieved by strangling up the transfer port.... The efficiency is supposedly higher.... and that's what I want to explore.... There is defintely something going on here that needs invesigation....

Bob