SpudFiles

For a high powered rifle, say... 300-1000 psi, would a slide valve +qev configuration still work? I'm just asking because those parts are usually rated to ~150 psi, the last rifle I built was fine but now I want more power, like a lot more... so if I wanted to build a high powered multi-shot rifle, what kind of configuration would you guys recommend? I want to be in 300 - 600 psi range, I don't wanna get too crazy yet, also how do you guys get your high pressures? CO2 tanks? Air compressors?

I've build a couple of versions of semiauto guns and getting them to work right requires a lot more effort than building a single shot gun. Plus you're limited to uniform ammo. Lol never expected I'd say it, but that's true. Building a bolt action gun will be a LOT easier. No one said you can't build a semiauto, but it will be more difficult and can be frustrating.

Now as far as parts are concerned...
I've been using 1/2" and 3/4" QEVs (european type) at over 500 psi for a while and I've never experienced any problems. I've even tried higher pressures, but usually the guns just get ridiculously loud and powerful even at 400 psi. So QEVs are not really a problem here.

3 way/slide valves are the real problem. I have 3 way valves with metal to metal seals and some with traditional seals which can survive such pressures, but in general they are difficult to get. It might be easier to get slide valves as they are used for PB guns so you can get versions rated to 850 psi or so, but I suspect that they'll make rather poor pilot valves, because of their low flow. Also If you want to use a QEV + 3 way valve + air cylinder combo they you also need to find an air cylinder, fittings and tubing that can safely operate at such pressures. Not that it's impossible, but it's a lot harder.

Spend some time playing with GGDT and simulate different designs - you'll see that upping the pressure gives rapidly diminishing results (especially if you're into smallbore guns). If you really want a semiauto gun my advice for you is to limit pressure to 200-300 psi otherwise you just run into too many problems. It's all about diminishing returns - sure that affects all pneumatics, but at some pressures it just gets really difficult to get the parts needed for a semiauto gun, so in a way they are more affected by that effect

hmm I always thought a three way valve WAS a slide valve O_o. These are the parts I currently have http://www.amazon.com/Amico-Inlet-Outle ... aust+valve, http://www.amazon.com/Amico-Series-Thre ... lide+valve, what pressures do you think I could safely take them to?

A slide valve is a 3 way valve. Just like every bike is a vehicle, but not every vehicle is a bike.

Should be ok up to 500 psi, but the slide valve might be difficult to operate (requires more force to switch)

ahh that makes sense, btw, any links on how to make a bolt action setup?