SpudFiles

ok cool i have seen the tutorial or something on how to make one of those so i think i will have to make one. but i still dont think this pvc will hold 300 psi or more.

Did you look at the edit in my post that stated to use those pressures?
I also said to make one out of copper.

ok cool i just saw the edit lol

i just missed it lol.

i have some steel in the garage, maybe that will work?

I have a half inch coaxial that I recently made, and had trouble with the piston too. My solution was an epoxy piston with three layers of craft foam (see picture or goodle it) that I had lying around. It now seals at ~15 psi and the power is amazing (went through 4 coke cans). The foam is not the toughest stuff, and if you have a sharp barrel it will be shredded pretty quickly, but as a semi-short term solution it is totally worth it. Good luck!

http://www.guildcraftinc.com/images/pro ... 20Asst.jpg

the problem probably was that your barrel wasnt lined up perfectly and that screw hit the barrel instead the seal. happened to me twice.

FordGTMan you were right. the second one i make i made it much better and it is lined up perfectly. now it seals and fires perfectly. except i have a leak and cant find and epoxy.

put it in some water. you can easily spot it then

brplatz wrote: i have some steel in the garage, maybe that will work?

Most definately.

High pressure co-axel