Thanx for the compliment, this was really the first custom gun I built from the ground up.
As far as increasing pressure with each stroke, the only mod that does that is the flat top piston and valve arrangement. Unless you can somehow make yourself a larger ID pump tube and matching piston, you aren't going to easily increase the stroke length, so the same volume per pump regardless. With the flat top piston you're doing a couple things. First off the piston I used is much more solid than the stock piston, so it doesn't flex under pressure and create headspace between the valve and the piston face. Headspace is going to be compressed air, air that is NOT in the valve, this is why you can only pump a stock 1377 so far before it isn't doing anything...that headspace is under the same pressure as the air in the valve, so nothing more goes in. This is the same idea behind the flat top piston, the flat top piston also creates a tight fit to the face of the valve and gets rid of even more headspace than the ill fitting stock piston with the cone seal. So when this is all done, you are actually putting more air into the valve per pump because there is less lost to valve to piston headspace.
I could go on forever, but if I do I might start sounding like "He Who We Must Not Mention", so I'll leave it at what I have explained already:)
Roy Weid at Mountain Air made my piston, which is also adjustable btw, so you can adjust its length to take up any headspace that is created as parts wear out, it's pretty slick, it also has an oil wiper ring to keep dust and junk out of the tube and the seals happy, and also has two piston o-rings to keep the whole thing tight as a drum. Pretty decent increase in FPS from a fairly simple mod, and yes, less pumping for more FPS, although with this mod you can also go past the factory 10 pumps because you are still putting air in because of the more efficeint nature of this setup.
Dan
