SpudFiles

At 500 psi my .54 cal qev muzzleloader launches a 300 grain patched slug at about 1000 fps. Barrel is rifled from a knight black powder rifle. 3/4 inch qev is piloted by a 1/4 inch ball valve. Gun is very accurate. This is my first post, any feed back is welcome.

finally something new, and a rifled barrel. Nice done. Upload a video with some shooting........

Nice build!
Is it single shot?

If not:
Trapping the exhausted pilotvolume with a second ballvalve would make it multishot pretty easily..
After the shot, close your "trigger"and bleed the secondary ballvalve.

The barrel makes it better than most!
Close that one back up and you can fire again...unless that QEV won't allow it.

That is one chunky looking QEV, where did you buy it/brand? Bet it has some real power at 1000psi!

What is on the pilot piping tee? A pressure gauge? Is it you who has a video up on YouTube? If not there is a so ilar looking gun.

The qev is 3/4 on all 3 sides for maximum flow. Qev is Humphrey and rated at 150-200 psi but easily handles 600 psi. I dont go much past that just for safety reasons not to mention it is a single shot and dumped the entire volume of air so at 600 psi it's already generating enough force to push a 300 grain slug so fast then I'm pretty sure we're breaking the speed of sound. the rear of the key has a 4000 psi paintball gauge on it and is join to the pilot side of the Q TV with quarter inch tubing and a three quarter by quarter inch bushing. and yes that video is of me on youtube not this particular build but very similar qev style builds. I will post more pictures soon I'm in the process of finishing the trigger area. I'll try to post some good damage shots and accuracy demo

Sweet, you posted it! I saw your videos on YT and they were very impressive, especially when you shot it through a steel pot like it was nothing. Is that the longest rifled barrel you could find? It would be nice to see how it performs with a longer barrel...do you have a chronograph?

Bring on the damage pics!

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Homemade qev air rifle build., 50 caliber bigbore.:

Neat stuff.

Not to be a nag, but @ 600 psi, you've likely near zero safety margin left in that QEV. Consider building something more suitable to the pressure you're using...it's really not that hard.

To properly test airguns, a chrony is HIGHLY recommended.

Regards,

Al

That valve has never leaked and its been in use for almost a year now. Also, the fine folks at Humphrey told me their 3/4 qev is rated like the rest on paper, but, its just for loability. The piston style qev in the valve is not like the alpha qev which uses a diaphram and is limited to what the diaphram can withstand before it starts to fail. I appreciate the concern for safty, but all my stuff is well kept and properly tested to see its actual limitations. The Humphrey qev started to fail at 800/900 psi when it tested ait. Alpha's qev fails before 500
I am interested in piloting the Q EV with an electronic solenoid valve and trigger switch if any one has suggestions. I've already tried with asco valves and never seem to get better result than the ball valve. Its just so hard to make a ball valve into a cool design asteticly. Also solenoid valve seems to be best for control of lots of potential variables.

Oh, quick question. Does your QEV use a diaphragm? I thought those types of QEVs fail at pressures like 600 psi

no there's no diaphragm per se as there is in the Alpha qev. The Humphrey qev uses a piston style diaphragm that is much more rigid and reliable under high pressure

Does this help?





You could attach some sort of shoulderstock to the handle...
It's merely an exhaust ..doesn't need to hold pressure, so you could simply run a couple of screws through it.

newenglandhvac wrote: Also, the fine folks at Humphrey told me their 3/4 qev is rated like the rest on paper, but, its just for loability.

I've no doubt that you spoke to their engineers...and informed them that you were using their product at four times it's rated capacity...and that they were still happy, smiling and generally pleased as punch with how you were using their product. :bs:

I also assume you meant "liability".

Regards, and please read below...