Muzzle Ball Valve

[Atlantis]

I was wondering if this idea would work:

I would put a say 1" Ball Valve on the muzzle of the 3/4" barrel, and have the gun be a coaxial, I would put a tee somewhere on the barrel outside the chamber with a tire valve so the air will go in the barrel then into the chamber, both chamber and barrel would be pressurized, the breech end will just be floating in the chamber, the ammo would be at the breech end like usual. When the barrel and chamber are charged the ammo will not move. When the Ball Valve is open the barrel will dump to the atmosphere then the chamber would dump int the barrel and push the ammo out.

The yellow parts are check valves.

I see no reason why this would not work, any suggestions would beappreciated. This design is easy to build because there is no piston or diaphraghm involved anywhere on the gun and it only has one moving part. This would also form a safety because th gun can only be loaded while the gun is not charged. I may have a few ideas on how to use the incoming air down the barrel to push the ammo to the breech then you would only have to insert the ammo past the filling point near the muzzle.

[PVC Arsenal 17]

hmmm.. that could be intersting. try it out and let us know how it works. shouldn't be expensive either

[Atlantis]

I've had the pipe for a while so that saves about 10 bucks. All I really need is the ball valve, an end cap, and a reducer. I'm getting together with my friend this weekend to make this. If it does'nt work, I can always turn it into a piston valve, which I really REALLY don't want to.

[SpudStuff]

I had an idea like that a while back but never got to making it. Mine used a 1.25 barrel with a 2" union/burst disk instead of the valve.

[boilingleadbath]

1) The air in the barrel does NOT leave instantly, thusly decreasing the pressure difference across the spud for a pretty long time.

2) The air in the barrel has mass... mass which you have to accelerate, which decreases preformance

3) What if the ball valve isn't open by the time the spud gets there?!

[FiveseveN]

It's true, it would decrease performance quite a bit, but it would be useful in some high-pressure designs (IMO anyway).
Another downside is the fact that the muzzle is absolutely vital to accuracy. If the valve is even slightly off-axis, you will lose both velocity and accuracy.
Nice to know your cogs are still turning, though.

[noname]

Yeah, and how exactly do you plan on getting a potato through a sprinkler?
Hilarious!

[Atlantis]

First, I said the ball valve would be one or two sizes bigger than the barrel.
Second, When did I say anything about a sprinkler?

Another part of my idea was to put the ball valve somewhere closer to the breech so there is less air in the barrel, just need to make sure the ball valve is the same ID as the pipe, if not I can bore it to the right size with my Lathe. I'll do some research on pipe and valve sizes. Maybe I'll use FiveSevens version of the HK G11 loader for part of the system.

[Brian the brain]

The ballvalve will not open fast enough, so the ammo will most likely catch on it.
A burst disk will work, but still not better than a conventional set-up.Only plus would be easy acces to puncture a burst disk, but whatever is puncturing the disc will be in the way of the ammo.

[benstern]

OR the ammo can be metal with a sharpened tip. metal would be good because it has density. you could add o-rings to the piercer too.

[PVC Arsenal 17]

So Atlantis, how's this project going? I'm starting one soon but it will use a union burst disc. I will also make one later to the same specs just in a standard burst disc configuration. I'll test them alongside and see how they compare.

This idea still fascinates me. I really wonder how it will work.

[Hotwired]

Not very efficient.

The pressurised air in the barrel is wasted.

Theres less of a pressure difference across the potato so slower acceleration = lower muzzle velocity.

It would also be very unreliable in firing, the ball valve would have to be perfectly aligned with the barrel for the potato to go through without catching unless you used an oversize valve.

[PVC Arsenal 17]

Or a burst disc.

[Insomniac]

Wouldn't this be nearly equal in performance to a normal ball valve cannon??

[Atlantis]

The ammo would never get stuck because I plan on using a Ball Valve bigger than the barrel, plus the fact that the ammo will be Airsoft BB's with a cotton ball behind them.

It might even perform better if the cotton ball did stick, then the air would'nt scatter the BB's once it leaves the barrel, not sure though.