SpudFiles

Oh yes and about full auto, can you make enough shells that it would actualy prove usful? or even make a mag large enough to hold them all?
I hope you prove me wrong!

here is the pistol I was thinking of

Sorry for the quadruple post I don't know how to put more than one pic in a post here is a semi auto consept pistol I thought of I know it wont work but here it is.

What I had in mind would work just like a simple blowback submachinegun - keep the trigger pressed to operate

Oh thats a submachine thompson oooooooooooooo. I don't get the picture diagram of the gun.

Jack, is there something to be learnt from the whole stepped piston thing we had with the autobb? If you made a short fat cartridge, then as this disengages from the barrel, you've suddenly got a much larger face for the residual air pressure in your system to work on. So you could use a stronger spring, which would help pierce the cartridge.

Just a thought.

SPG wrote:Jack, is there something to be learnt from the whole stepped piston thing we had with the autobb? If you made a short fat cartridge, then as this disengages from the barrel, you've suddenly got a much larger face for the residual air pressure in your system to work on. So you could use a stronger spring, which would help pierce the cartridge.

I'm very aware of this factor and certainly think it's to blame for the failure of this attempt to eject the cartridge from the breech.

Ideally, purely in terms of simplicity of construction (mostly the lack of concentricity worries) and aesthetics, I'd want the cartridge to be the same diamter as the barrel. However, this by definition leads to reduced air capacity and limited flow, and as you mentioned cuts down on the area avalable to the air to push out the spent cartridge.

With this design however, if I get the cartridge heads machined then I have no such worries. I'll speak to my machinist friend tomorrow and see what can be done.

jackssmirkingrevenge wrote:
With this design however, if I get the cartridge heads machined then I have no such worries. I'll speak to my machinist friend tomorrow and see what can be done.

Hey jack did u realize that if you machine the cartrige then it may become too heavy. Then it might take more energy for the system to reload. I think we should look at real bullets, look at the expansion of gas> how many times the original volume, the mass of the shell and the mass of the bullet. Like this we could do a comparison with our stuff here.

Firearm cartridges generate anything between 10,000-60,000 psi of pressure at the moment of firing, and they do this in a tiny time interval - I don't think any comparison would really be valid in this case, the difference in stored energy is far too great.

I see your point about heavy cartridges though, and if they're going to contain pressure then it's always going to be an issue - but as SPG pointed out, a wide cartridge will give the air much more surface area t oact on and make it easier to extract. My combustion cartridge experiments proved this point pretty well

Ant linked a picture to (I believe) the Spyder paintball gun. It has a small air chamber (with a line leading to it) that kind of floats between the hammer and the barrel. On firing, air is released from either side of the air chamber. How about making a cartridge with the same feature?

Hawkeye wrote:Ant linked a picture to (I believe) the Spyder paintball gun. It has a small air chamber (with a line leading to it) that kind of floats between the hammer and the barrel. On firing, air is released from either side of the air chamber. How about making a cartridge with the same feature?

Hey, beautiful idea! Btw the animation was of a tippmann prolite.

The problem with this though is that the cartrige doesnt really move back, this could make it hard to make a ejection system, but it could recock the hammer with spring.

Interesting thought but that adds complexity and weight to the cartridge, limiting its mass production potential. not only that but if there is air pressure on both sides of the cartridge, there wouldn't be a pressure differential to move it back - of course the bolt would move back, but if you somehow attached the bolt to the cartridge, the air pressure would still cancel out.

The bolt might have an arm that works the loading port(as this one does) and also hooks the cartridge on the back stroke.
Of course this idea might be more of a power cartridge idea rather than a cartridge that also contains the projectile.
This idea might also work strictly as a compact power source. You could probably make these and pump them up to high pressure and get a couple of shots (at least) out of each one.

That's an idea, however personally I'd rather have one-shot-per-cartridge and see that brass fly

jackssmirkingrevenge wrote:That's an idea, however personally I'd rather have one-shot-per-cartridge and see that brass fly

lol. look at the smoke that is created. I thought only the ak47 was crude> the barrel in this vid moves as well, damn!