Gas operated Marble gun.

[Redcoat]

Hi all,

I thought of this idea(but im sure someones done it before) in maths class and i just wanted to hear your thoughts on improvements and modifications i could make.
http://science.howstuffworks.com/machine-gun5.htm this link is just to show you how they work if you dont know .

thanks.

[jackssmirkingrevenge]

Sorry to burst your bubble but I'm almost sure it won't work at spudgun pressures. Remember that firearms that use this system have chamber pressures in the range of 30-50,000 psi far higher than anything you could have in an amateur pneumatic.

Of course there's only one way to find out, feel free to prove me wrong, but I'm pessimistic.

[Redcoat]

ah well.i'm not going to attempt it unless i know or have a really good idea if its gonna work so yeah.
I just wonder.........................mmmmmmmmmmmmmmmmm. i wonder if i had another tube fram the same blowgun like an air hose with a fork in it leading to the barrel and the piston but with the piston one longer so it takes a longr time to get there and so it goes full auto that way.Though it would have been nice to have it like a real gas powered gun.

[jackssmirkingrevenge]

I think you should be looking at the direct blowback system for inspiration, which is what low pressure firearms such as the Makarov PM use, and also the mechanism I adopted for my cartridge fed prototype.

If you want to stick to a separate gas line for the piston, then having the line fed directly from the valve has a much better chance of working. It would be a good idea to include a ball valve on the line, so you could adjust the flow of air until you get optimum performance.

[Redcoat]

yeh ive already designed a blowback system for a pistol i am gonna make when i get some cash.

But if its not too much too ask you could you please draw me a diagram or describe to me in detail your seperate gas line idea? you dont have to but im having trouble visualizing it.

thanks.

[jackssmirkingrevenge]

idea:

note that the ball valve is only there so you can adjust the airflow until you can find an ideal position for the best performance, once you so this you can lock it in place.

[lukemc]

what if you used jacks idea but the piolot of the main valve moved the piston giving it a fraction of a second for the marble to drop

[Redcoat]

ill try and see if i can get some prts for jack's idea but now that ive slpt on it (im only half awkake and ikep missing keys and my damn stubbby fingers )
i think i might give the direct bolw back a go.

The thing is i want a semi auto or a fully auto marble gun which still has alot of power behind it I might even try and build it into a BAR 1918 i really like those and i want the same umph that the BAR has like this



Edit- http://www.petitiononline.com/hds2468/petition.html

[jackssmirkingrevenge]

again, shouldn't the air hole be between the projectile and the bolt?

[Redcoat]

yeh what that is a picture of is rior to the thing loading that is the gun when the Marble comes up from the magazine and before it gets pushed into position.When it fires its all up in place with the air hole in the middle.

im just wondering if there will be enough pressure to push the bolt back as well as shoot the marble a considerable distance.

[Redcoat]

I know this is a double post im sorry.

Would i just be able to have the barrel with an inverted magazine without a piston and just have air going and propelling the marbe forward and then the next marble falls down and caught in the jetstream and so on....?

i didn't think it would work because air would go up the magazine but it would be cool if it did.

I would like to be proved wrong.

[Redcoat]

I know this is a double post im sorry.

Would i just be able to have the barrel with an inverted magazine without a piston and just have air going and propelling the marbe forward and then the next marble falls down and caught in the jetstream and so on....?

i didn't think it would work because air would go up the magazine but it would be cool if it did.

I would like to be proved wrong.

[jackssmirkingrevenge]

triple post actually :p

You don't have to have the magazine that's exactly the same diameter as your barrel...

are you planning on pulses of air from your valve, or a continuous flow? In the case of a latter, make an MMG in the case of a former, how about a paddle to interrupt the flow of BBs from the magazine, as done here

[Redcoat]

whats an MMG?

Touche on that "triple" post i don't know how that happened....

And i may try that paddle thing if my other ideas fal.

Anyway, i am having a continuous flow and i would like to know what an MMG is.

Thanks.

Edit- HOw do you get Spud Bux without posting?

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[skinner]

Marble Machine Gun