it is based on btb's piston http://www.spudfiles.com/forums/viewtopic.php?t=6214&
this is what is like
the tapered disks hopefully act as a one way valuve

the neopreme barrel sealing surface

the piston on top of 2" pvc (my chamber size)

a diagram of it

the friction seems pretty high but i have never done a piston befor so i dont know what to look for



