What's your Holy Grail of Spudguns?

[Hotwired]

No worries, I get five or six shots that punch through a cardboard box at 20m from my cannon like that.

Incidentally. My current grail is a semi automatic inline cylindrical ammo feed from behind the barrel.

Not into the side of the barrel. Through the back

[iknowmy3tables]

a golf ball bbmg haha if possible

well I guess the way some people build gb cannons meant for short burst of golfballs like the Vogt design
its sorta like a very small ammo capacity gbmg too small for my satisfaction only one burst

Joel made a sort of ping pong cloud powered by a vacuum
http://spudtech.com/content.asp?id=10
third gun from the bottom

maybe a high pressure scuba tank with an accumulation chamber will get you enough air for that

[rna_duelers]

Supersonic Golfball Hybrid.

[SPG]

Incidentally. My current grail is a semi automatic inline cylindrical ammo feed from behind the barrel.

Not into the side of the barrel. Through the back

What capacity are you hoping for in your magazine, if it's quite low that should be really easy.

[Hotwired]

Fairly low, 3-5 would be fine.

[jackssmirkingrevenge]

I would definitely like to see a semi/full auto design that can eject cartridges, the latter premise is purely for the "cool" fasctor but after all, that's what spudguns are all about.

[SPG]

Fairly low, 3-5 would be fine.

Constant air source, or on-board precharged? And what calibre?

[octane89]

Incidentally. My current grail is a semi automatic inline cylindrical ammo feed from behind the barrel.

Not into the side of the barrel. Through the back

I was looking at this and think it can be converted for spudgun use.
http://science.howstuffworks.com/machine-gun7.htm

There are other systems they show like the "recoil" system which may effective too.

[jackssmirkingrevenge]

I was looking at this and think it can be converted for spudgun use.

gas system

That system has often been proposed but I doubt it would work for spudguns, purely befecause of the pressures involved. Firearms that use this system are typically rifles (with some exceptions like the Desert Eagle) operating with chamber pressures of 30-50,000 psi, meaning there's more than enough power to spare to operate it.

For lower pressures typically generated by pistol cartridges, the direct blowback system is preferred, which makes more sense for spudguns.

[POLAND_SPUD]

JSR we all know what is your holy grail.... a spudgun made only out of epoxy and firing epoxy projectiles, possibly using epoxy instead of air

[jackssmirkingrevenge]

How about using the exothermic reaction of curing epoxy could heat up the air in a chamber to generate enough pressure to fire a projectile

[judgment_arms]

I would definitely like to see a semi/full auto design that can eject cartridges, the latter premise is purely for the "cool" fasctor but after all, that's what spudguns are all about.

I’m working on it, Jack.

As for operating systems, I don’t like pure-blowback; sacrifices way to much power. I’ve bean leaning towards recoil, or my gas-assisted recoil idea.
All I need is some time, money, and a good size chunk of 2.5” SCH40 PVC and I’d build a prototype.

[Hotwired]

@SPG: unknown and unknown but you can take it as a given that it's not for firing pellet sized ammo.

@octane89: I'm very loathe to snaffle projectile propulsion power to recock a mechanism.

[POLAND_SPUD]

cartridges would allow to use different types of ammo in semi/fullauto guns...
for example marbles, flechettes, potatoes in the same gun etc.
so I wouldn't say that ejecting cartridges would be only for 'cool' effect, since 'spent cartridges' would have to be removed somehow to allow semi/or full auto fire

[SPG]

@SPG: unknown and unknown but you can take it as a given that it's not for firing pellet sized ammo.

Yeah I just knew you'd say that, but assuming it's not for pumpkins this might just work.

We'll start with the combined barrel/magazine. This is going to just be an extra long barrel, with an end cap on one end and a "hop-up" somewhere along it's length (say 6 or 7 cylindrical ammos worth along). and some ports about 1 ammo length back from this towards the end cap.

Now the chamber, imagine a co-axial gun, but the barrel runs right through.

Now the action. Like a co-ax it relies on a piston moving. But unlike a normal co-ax the piston slides back and forth along the barrel exposing or covering the port.

Voila....