A friend and I are building a 3" piston valve air cannon made from metal. We are planing to to do shooting at around 400psi or more we also might be mounting it to a car mayby if not a stand
![Very Happy :D](./images/smilies/icon_e_biggrin.png)
Edit:
Just some questions:
1.what is a good sealing face for high pressure?
2. what is a good bumper?
3.What is a good strong and light material that i can use for the piston?
4.Will i need a spring if a i fill it from the chamber and if so what type of tension should the spring be?
5.If i fill from the chamber will i need a o-ring around the piston?
here are some pics of what we have:
all three parts:
![Image](http://img163.imageshack.us/img163/2199/dsc0720h.jpg)
this is where the piston will be housed in:
![Image](http://img838.imageshack.us/img838/649/dsc0722vj.jpg)
Size comapairson:
![Image](http://img809.imageshack.us/img809/5366/dsc0725r.jpg)
the tee:
![Image](http://img848.imageshack.us/img848/191/dsc0724z.jpg)
There are still alot of things that we still need to buy but this will properly be a long term project because of the cost of all the parts.
Cooper.