The design is simple:
1 compression chamber
1 pneumatically modded ballvalve
1 barrel
How it works:
you put water in the chamber, heat it with charcoals around it and wait until you get a decent pressure and open ballvalve.
Very simple, and Mythbuster throwed a 22 pounds projectile at 1 mile with 60 psi
This is very practical because you only need to put water in the chamber and wait, and after a few shot, the chamber is enough hot to fire at a pretty good rate of fire and no need of aircompressor.
(its sure it is not going to be in pvc...)
Does this already had been done here before?
I would like to see one of the spudfiles members do it











