The Hill Max power kit came with his http and bit to open up the barrel port. I did drill out the barrel and polished the chamber. I was thinking about buying a new Marauder with the Lothar barrel and going for high power. I just can’t find any high power threads anywhere. Does the JSAR valve have a higher air output potential than the hill valve? The bigger question was what happens with a .25 valve in a.22? Thanks for the input.