SpudFiles

I just saw this post http://www.spudfiles.com/pneumatic-cann ... 24091.html and since it was posted a while ago, I'm not sure if OP is still around to answer my question. When the chamber/stock is pressurized and the slide valve is opened, how much pressure actually goes into that little firing chamber in the QEV? I mean I might be interpreting this wrong but he says he pumped it to 150psi, so when the slide valve opens wouldn't the pressure in the firing chamber raise by just a tiny amount?

Maybe you're not getting how it works, here's a pretty exhaustive explanation: http://www.spudfiles.com/pneumatic-cann ... ev#p365630

yup, I thought how that works, my question was how much pressure is in the firing chamber after it's charged, since the firing chamber is so small?

Pretty simple stuff, the pressure will equalize on both sides. If the hole is small it might just take a bit longer.