Do I have to have a chamber that bloody big? I could always use a fire extinguisher as a resevoir, attached to a chamber with a ball valve to refill the chamber after every shot how big does my chamber have to be? I looked at GDDT or whatever it is and well yea.. a lot of data going on there and I h...

How the flip do you make shotgun shells :0 See my edit ;) Ah cool! If I go for a 3/4" (19mm) bore, I won't be able to use copper pipe, I'll have to get steel I'm assuming you're in the UK, can't you get 22mm pipe? I'm from Australia, mate. G'day :P I read somewhere you said UK copper was thin and c...

The ID of my barrel will be either 10.88mm or 17.01mm. Depending which copper pipe I choose. I would love to use marbles but I'm not sure of there exact size yet. I can always cut aluminium rods up to make bullets. Marbles are poor projectiles, they shatter easily and have poor sectional density. I...

Low budgets usually take HPA out of the equation. Are you set on semi-auto or will a single shot high powered pneumatic do? Have you had any thoughts as to what calibre and sort of ammunition you would use? Semi-auto would be awesome, but in saying that I don't mind having to manually put another b...

What pressure do you want to run at and what's your budget? I have no idea of what pressure gives what results. I've only ever used spray and pray combustion cannons. I want it to be powerful enough to theoretically take down small~medium game. But I won't be using it for this purpose. I wouldn't w...

WOW JSR you are seriously an asset to this forum. Thankyou for your response Wyz made that all look so simple! Do you think you could somehow attach a trigger to the slide valve so you can hold the gun normally and fire it? then maybe you could put a spring behind the trigger to push the slide valve...

hmm good reading, but a few questions 1) JSR, how does this three way valve work? do you mean a QEV? 2) I could try a slide valve, but how would that work better than a blow gun? 3) Does the speed that i move my hand effect how fast the projectile exits when using a slide valve? 4) How do you make a...

A coaxial as a gun in which the camber and the barrel both share the same axis. You have your barrel down the center of a larger chamber. This eliminates the use of much of the plumbing which makes up a typical pnuematic. http://nighthawkinlight.wonderhowto.com/how-to/make-powerful-pvc-air-cannon-w...

There are much more powerful designs that use the same or less fittings than that gun. Maybe he's a member here, but that thing looks like an accident waiting to happen. I wouldn't trust that spray can chamber with 80 psi. You should consider a copper coaxial pneumatic to start playing with air in....

Hello, Unimportant info My old combustion cannon has died so I've been looking to build a new one, I came here to this site and this is the first time I discovered pneumatic cannons, so I've been reading about them for a while and now I understand how they work and various types of valve etc I have ...