SpudFiles

hi...am gng to make one pneumatic spud gun.am using 250psi pressure and hav a muzzle velocity of 350m/s .i hav doubt about the type of pipes,valves and the glue to be used

Make it out of stainless steel like Chaos's gun: http://www.spudfiles.com/forums/s400-sn ... t7862.html

pri wrote:hi...am gng to make one pneumatic spud gun.am using 250psi pressure and hav a muzzle velocity of 350m/s .i hav doubt about the type of pipes,valves and the glue to be used

@Pri
Welcome to the forums.

If you could please make an attempt at using proper grammar so that we can understand your question, maybe we can help you.

I'll try to translate your post:

"Hi. I'm going to make a pneumatic spudgun. I'm using 250psi of pressure and (hope to?) achieve a muzzle velocity of 350m/s. I have doubts about the type of pipe, valves, and glue to be used."

For 250psi, you'll need AT LEAST sch80 pvc, and looking towards metal would be a very good idea.

For a valve, a piston valve would be preferred if you're capable of making one. Not many store-bought valves that have decent opening times can stand up to that pressure. You might be able to find a QEV that can.

As to glue, use whatever kind matches your pipe, and ONLY that kind.

What's your pressure source?

What size barrel and what type of ammo do you intend to use?

Peace,
Pete Zaria.

No one seems to have pointed out yet that 350m/s is faster than the speed of sound, so you may have some problems there, 250m/s is a much more reasonable speed to aim for and still fairly impressive.

you would need to use helium if you want to break the sped of sound because it wouldnt happen even with 1000 psi with compressed air.

hi wrote:you would need to use helium if you want to break the sped of sound because it wouldnt happen even with 1000 psi with compressed air.

Not quite true. It is possible to go supersonic with regular air, but it's not easy to do.
However, using pressures as high as 1000 psi, you could probably manage it, most likely because of the "shock heating" phenomenon.

Pri, is this your first gun?

If so, you really should start with 120 PSIG, Sch40 PVC pipe and a basic valve.

Going for supersonic on your first gun is a great way to waste a lot of $$$ and/or hurt yourself.

you would need to use helium if you want to break the sped of sound because it wouldnt happen even with 1000 psi with compressed air.

at 100 psi with my contest gun i got 1054 or something around that with a 1 inch marble...


@pri for ur first gun do a basic one..start out wiht a sprinkler... buy one from a local irrigation store or offline and modify it. it will shock u if this is ur first gun

As for pipe, I think you should go for threaded metal pipe for high pressure.
Also, now many storbought valves can take, 250 psi and still open within a decent time. If your confident in your skills you should make a piston or diaphram valve. good luck with the 350m/s thing.

at 100 psi with my contest gun i got 1054 or something around that with a 1 inch marble

1054 what?!