i don't have the right size o-rings for a floating setup...i do have some bulk o-ring material that i got from work that i could use, but what works better? floating or reg. with an equalization hole? oh and i think the reason i cant post pitures is because they are too big? anybody have that problem?

You guys rock!!! I took the spring out of my sprinkler valve and had much more power and the piston does not reseat! i can charge the cannon and hear that piston seat and the pilot valve doesn't screech like it did before...now i'm going to try to get all i can out of it to see how far i can huck ...

I have foam for my bumper. and yah i kinda thought that i needed an o-ring on my piston. i've seen some real rough looking pistons that worked well without them though? should i use some wood to take up some of the pilot volume? also has anyone tried removing the spring in those sprinkler valves ...

Ok im sick of tring to find the forum for this topic!I built a 2'' piston valve, the piston is machined out of solid teflon and is hollowed out to save weight. The tolerances between piston and pilot chamber are very good about .025''. My piston seat is 1-1/2'' pvc, the pilot area is as small as i ...