Page 1 of 1

Special Cartridges/ammunition

Posted: Sat Mar 27, 2010 1:30 pm
by GuyFromAvalon
Hi Guys,

First, I'm new here and will post pictures and specs of my first pneumatic gun soon.

Meanwhile, I have a question: I'm sure everyone in here has at least once thought about a System that solves the main problem of pneumatic guns (at least our homemades): The difficulty to fire multiple shots. So I thought about building own Cartridges that would fit into the barrel, giving us the advantage of more space and less weight due to the missing chamber, which would not be needed anymore. I know that is a bit like a normal gun, but would base on the old priniple of presurized air. I have attached an image of what I thought could work. the two "clippings" (didnt know how to call 'em) go through two small holes in the steelpipe and hold the bullet in place. WHen the Copperpipe moves backwards, the clippings release the bullet. To prevent them from "self-ignition" I thought of a spring that fills the space between the endcap and the copperpipe.

Now to the question, do you think this would work, too? And if yes, what size of Pipe would you think is needed to push the bullet at least 150 yards or so? (not much less, I think that is the minimum needed)
And which preesure of course?

Hope this hasn't been asked before, I used the search but didn't find anything.


:!:

Posted: Sat Mar 27, 2010 2:05 pm
by deathbyDWV
This has been brought up many times before...

Just wait for JSR. He's worked on this and will give you some links...

Edit... Well actually not this specific idea. To get decent power you would need high pressure. With high pressure the clips won't hold.

Posted: Sat Mar 27, 2010 2:06 pm
by Demon
The idea of clipings is pretty good, exept that every bullet would need a o-ring and holes ...

A bolt action could be done, a spring loaded bolt pushes the cartidge in the barrel and it triggers itself .

Posted: Sat Mar 27, 2010 3:23 pm
by iknowmy3tables
giving us the advantage of more space and less weight due to the missing chamber,
I'm afraid that you are mistaken my friend, as you now know preloaded cartridges have been proposed many times before and even tested, and the major difficulty of preloaded cartridges is that the chamber has to be contained within the cartridge so typically most preloaded cartridge designs have involved bulky cartridges and/or low power due to the small chamber sizes
Meanwhile, I have a question: I'm sure everyone in here has at least once thought about a System that solves the main problem of pneumatic guns (at least our homemades): The difficulty to fire multiple shots.
well there are plenty of muti-shot pneumatics guns check out the pneumatic cannon showcase, they typically use a regulated air source like an air compressor or regulated CO2 nitrogen or HPA, it's actually fairly easy and not that uncommon to make a multi-shot pneumatic

Posted: Sat Mar 27, 2010 4:57 pm
by GuyFromAvalon
Ok first thanks for your answers. I Know its possible to
build Multi-Shot airrifles. Though i think its still more complicated
to Build them than simply load à bullet ànd Fire it.
But anyhow, to my fore-Poster: i don't think you underytood
my intentionn. I thought about Making the Gun lighter,
ànd saving the Space Used for the chanber ànd the weighz needed. I use a
Steel chamber Because i think its Most reliable. Saving that Wohls really
make à difference. Ànd i found one with Screw threAdings. So I could use
endcaps instead of Some weird pressurefittings.

But ok, i will try to make some ànd Test them. I don't think
the clippings wouldnt hold the bullet As the copperpipe shall go over
them Till the end. That would make it impossible for them to Switch out.
its cleAr that i will lose power but that is ok. Do you think
pumping the steelpipe to 200psi would Be enoigh when the it had
à length of 10centimeters? Ànd i really beg your pardon for the horrible spelling, I had to Write this on my iPod, which really Sicks at typing.
Greetings

Posted: Sat Mar 27, 2010 10:32 pm
by Marffy
That could work, or you could get/make a semi-auto valve that can handle HPA. but a cartridge would be cool. i'd like to see more cartridge pneumatics.

Posted: Mon Mar 29, 2010 1:42 am
by jackssmirkingrevenge
Floated around a similar idea here:

Image

Have a look through this thread ;)

Posted: Mon Mar 29, 2010 9:39 am
by GuyFromAvalon
Ahh, thanks JSR, found that in the late afternoon yesterday. FIne Work, have you already brought your other cartridge into a working state?

Posted: Tue Mar 30, 2010 12:17 am
by jackssmirkingrevenge
The reason I never actually completed any of my prototypes was that I never managed to achieve the elusive "blowback" effect where the cartridge would also have enough energy to eject itself and cycle a semi/auto mechanism, however for a single shot or manually operated bolt action they would certainly be adequate.