QEV Rifle

[lonewolf1828]

Hi guys im comming from another forum that revolves around airguns that quickly shot me down. I am looking to build a 50 cal. rifle(for target practice). I want to have a similar trigger such as in this video but i am having trouble finding the part and how to incorporate it. As for the QEV I was looking at these:
1. http://www.ebay.com/itm/Pneumatic-QE-04 ... SwuhhXURMh
2.http://www.ebay.com/itm/Pneumatic-Quick ... GCAWCRprUg
3.http://www.ebay.com/itm/Quick-Exhaust-V ... SwdG9XRI9Y
4.http://www.ebay.com/itm/Pneumatic-QE-04 ... SwgQ9VlTm0

Which size would be best?

Also for accuracy how would I be able to incorporate a muzzle loading barrel into the mix? Possibly turning it town to fit copper piping?

operating pressure will be around 120-250 psi.
looking to make this a muzzle loader btw.
Thank you guys and I hope I came to the right place.

[Gun Freak]

Welcome to SpudFiles! I hope you have a better experience here. In my opinion we have always been very welcoming and open to helping new members get into the hobby.

The trigger mech in that video appears to be homemade at first glance. Probably a push button valve of sorts. Although they are very simple and easy to make, you probably won't want to do that as a beginner. Aim for a blowgun like the ones used with air compressors. Add a tee fitting behind the QEV to install a fill port.

As for the QEV choice, I would go with the second link as that is the most common I have seen over the years, and they can take very high pressures. Well beyond what you plan on using! Be careful with the threads on those valves though, I think they are BSP and not NPT, so you may need adapters.

As for incorperating muzzle loading I'm not sure what you're asking. Muzzle loading is just dropping the ammo all the way down the barrel, so there isn't anything to implement. If you're asking how to implement a bolt action system, look around the pneumatic showcase for examples and I'm sure you can come up with something. The easiest way is to just cut a hole in the top of the barrel to drop the ammo in, and making a sleeve which can slide off the hole and then back over it. This isn't very efficient though, just easy to make.

Hope that helped! Good luck!

[AlfiePB IanB]

Welcome, I am sure you will get on great here, full of helpful and knowledgable members not like some forums. People are open to new ideas and designs willing to help and guide you even if your design is a impractical or a non-starter.

One of my favorite forums, have a look through the members cannons forum for ideas and inspiration, good luck.

With the QEVs I found the ones like the 1st and 4th link are described as 3/4" but this is just the pipe fitting size and the actual flow through the gold port is restricted to a lot smaller than 3/4". Not sure if you have them in the US I have found Parker QEVs to have great flow and fast action, I have used mine well above the rated spec of 150psi, I don't necessarily advise it but mine withstood 400psi without problems. Slide valves are a good cheap and effective way of allowing both filling of the cannon and venting the pilot, I have seen people operate these via a mechanism to give a simulated trigger. Also with the pressure you are using I would have concerns about using a 1/8" QEV (link 2) with a half inch barrel, not sure if I am right on this but I would go for a 1/2" or 3/4" QEV to maintain a less restrictive flow to give maximum velocity. The link to style are readily available in a variety of sizes ranging from 1/8", 1/4", 3/8", 1/2", 3/4".