SpudFiles

Hello. I was brainstorming a method of quickly reloading a simple (or complex) combustion spud gun. Eventually Gas-operated reloading system used by guns such as the AK-47 got me thinking about applying that principle to the potato cannon.
The attached video shows how such as system, in my mind, would work. Please excuse my total lack of scale, it's just an animated sketch to get the idea down.
(It's not in the video, but mid barrel, there should be a wye pvc section with an appropriately angled section to port the gas from the combustion down to the breech).

Is there no video? I am a newbie to the forums, could I reply with the included animation somehow?

There's no video.

Try uploading it to youtube and then attaching it to your message.

Hello and welcome to Spudfiles. your animation or video you tried to attach did not seem to work. Also this idea has been thrown around many time before. The general conclusion is that the pressures in a potato cannon are not great enough to cycle an action like what you are talking about. real guns work at pressures in the thousands of psi not the hundreds like most spud guns use. You can use the search button to find several other post just like yours and get some other views on it. I hope this doesn't discourage you in any way. If I were you I would check out the cannon showcases and get some ideas going for your build.

There we go.

geardog32 wrote:Hello and welcome to Spudfiles. your animation or video you tried to attach did not seem to work. Also this idea has been thrown around many time before. The general conclusion is that the pressures in a potato cannon are not great enough to cycle an action like what you are talking about. real guns work at pressures in the thousands of psi not the hundreds like most spud guns use. You can use the search button to find several other post just like yours and get some other views on it. I hope this doesn't discourage you in any way. If I were you I would check out the cannon showcases and get some ideas going for your build.

thanks for the insight!

Thats a cool idea, but it could easily be simplified; have you thought of using an air cylinder to aid in loading?

geardog32 wrote:Also this idea has been thrown around many time before. The general conclusion is that the pressures in a potato cannon are not great enough to cycle an action like what you are talking about

It has been implemented successfully; it is used here and is able to handle semi and full automatic cycling

Perhaps, but the thing that attracted me to this idea was the gas cycle. I like the air cylinder as an aid is an attractive prospect...

read this

That looks quite crude, I'm sure there are more elegant ways of using a gas piston, such as driving a sleeve over the barrel.

You should also consider the blow-forward style bolt:

I can see this potentialy working, but with the low pressures from plain combustion I doubt it would cycle in a dry-fire test. With a projectile in there keeping the pressure up I don't see why not, but you may need to place the port farther up the barrel than you'd expect.