I mean, i just dont wanna have to order them, and im going to be shooting a lot and not recovering them. The dollar stores sell them pretty cheap but itl add up after a couple hundred shots.

Yeah its not a very good fit, but it can't always be tight can it? anyways though, any other suggestions for ammo? I know marbles are popular, im just looking for something a little cheaper and easier to get.
Nick

I want to make a long (for a pistol) coax pneumatic piston gun. Im trying to find good cheap ammo and i looked at my golf tees and thought, hmm, maybe those could be used and would drag stabilize as long as the barrel is long enough. I wondering if anyone has tried using wooden golf tees as ammo bef...

If i can find the right size o ring at my local hardware store im going to do a floating o ring. I shot the cannon a few times from 70 psi up to 92 psi and it looked hilarious watching the ball fly, it mustve cleared 1000 feet within 3 seconds or maybe less but it was dancing around like a wiffle ba...

It works well, but it doesn't open anywhere under 40 psi, and at that point the golf ball is going ridiculously far.. I want to be able to do lower power shots so im going to make the piston a littler better with an o ring and built in check valve. Then ill take some video on 100 psi. I might also t...

Alright today as you guys told me i plugged the eq hole, wrapped the back in duct tape for a hand push fit, lubed everything generously with petroleum jelly including the sealing face. Test shot on 45 psi looked to have the same velocity as my other cannon had on 110 psi, and thats 1300 foot distanc...

Alright, thanks for the replies. Tomorrow ill add more tape and block off the equalization hole and see how it does.
Nick

I just made my first piston valve cannon. It is a 2" barrel sealing piston valve housed in a 2" pvc tee piloted by a modified 1 inch jar top sprinkler valve with blowgun. The piston is a 1 1/4" coupling with a plug on the front with a pretty standard sealing face. The seat is 1.5" pvc. At first i co...

That's not a bad idea. Also, would using sdr 21 1.5 inch pvc for the seat of the valve have reduced sealing ability to sch 40? If so I can coupler it to some sch 40 but I would prefer not to.

Yeah I figured they're probably available online. I think I will be able to do a 2 inch tank and still make the valve and chamber coaxial with the barrel. Just have to angle the tank off in to different shapes but nbd. I would make a drawing on paint but my computer doesn't work and I'm on an iPad.

I know dwv fittings should never be used in pressure situations, but I want to make a full coaxial cannon with the barrel running inside the tank. I would have to use a 3 inch tank though. The only problem is the only way to get from 3 to 2 inch pvc is with a dwv bushing like this one http://www.low...

Alright. If it doesn't fit good enough I suppose I can just do the full hub design. Wouldn't be much harder.
Edit: not sure what a coaxial piston is. Mine is going to be a barrel sealing piston housed inside a 2" PVC tee.

My bad, I dint't make that post clear enough. I meant the piston made simply from a 1 1/4 coupling and an end plug with a neoprene washer bolted below a metal washer.

Yeah I just really don't want to go the route of a burst disc, even though the performance is great, I don't want to have to make the discs. I think I would really enjoy making a piston valve, and a simple one at first. Do you guys think the piston I described on my post from yesterday would work? E...

I think I might have found a compromise for myself. I looked at hubb's tutorial and I think I'm going to make a simple piston with 1 1/4 coupling and on the barrel end a plug with a piece of felt and then a neoprene washer and then a metal washer on top of that. I'm going to skip a check valve and j...