use a qev, pump the tank up to 80 psi use a ballvalve to pilot, create at the other side of the ballvalve a pressure of 60 psi, during the shot the pressure will drop only a little resulting in some sort of pulse.

just an idea

Why did you put a ball valve behind the QEV on picture 3 and 4? ( at the exhaust side)

pcp tanks on hightech airguns are able to handle 250 bar ( 3600 psi ). I don't know your skill around pneumatics however if a homemade pcp tank explodes and a very little piece of shrapnel hit's you... It won't be nice.

Hotwired wrote:Its a special kind of mod called "using steel pipe and iron fittings"

Not the gun, I see why the gun can handle 30 bar, but the pump the most pumps don't survive 25 bar so 30 is amazing for a hand pump.

very nice gun 8) what velocity do you get out of it? and the pump you use what kind of mod did you do to get it up to 30 bar ?

no u said it right but anyway ur gun looks a bit akward isnt it hard to fill with that wierd chamber?? No, it doesn't matter how you make the chamber as long as you don't create any bottle necks, why would it be hard to fill? :? The camber looks weird because I had to make a choise; I could search ...

I have made it just to preform thats why I didn't care for portability ( I'm not gonna walk around with this thing on public streets :D I haven't shot it over a chrony so I don't have a idea at what sort of speed the projectile travels (it is faster than my airgun and that gun shoots at aprox 200 m/...

Well here go’s :D My first pneumatic cannon. I named it Mjolnir (after the hammer of Thor). It is completely made out of copper and brass pieces. It took me about 3 weeks to build and a lot of checking for leaks. The whole thing cost about 175 Euros. http://img183.imageshack.us/img183/2464/s3010010a...