High pressure, LARGE automatic valve?

[Number21]

I'm working on building a giant sized exact replica of my real shotgun with probably a 2" barrel. It will all be made from metal, and I'd like to try and use it at around 300 PSI

So that brings me to my question, where can I find a diaphram or other type of fast opening valve, rated for 300 PSI?

One thought I had would be a standard ball valve, with a fast pneumatic ram to open it. But I'd rather find a diaphram valve...

[jackssmirkingrevenge]

I hope you have a considerable budget

[jmeyer1022]

thick thick burst disc

[jackssmirkingrevenge]

thick thick burst disc

That won't help if he wants it "auto" though...

[rp181]

keep in mind its 175$ for a solenoid, it will get much higher for faster opening valves. This butterfly valve.