SpudFiles

What i always wanted to have in the domain of spudgunning was an auto/semi auto gun(sniper of preference). It made me make some huge waste of money( like my semi auto paintball gun and my paintball bbmg(wich works, but i dont have aircompressor so... it lies in my room)) but now i think that i have a very simple and cheap design of an preloaded AND charged catridge. You simply spray hairspray or propane in it and seal it with a paintball ( there is a seal with duct tape around the paintball). The ignition occurs in the catridge.
With this idea, i hope being able to achieve a sniper rifle looking gun and to make a magazine system, but i dont really know how to make it for now, but i will think of it.

The ignition is in the bolt and connected to the trigger by a pushbutton( probably a 5v bbq sparker).

And i aslo have a question: what fps will i get with a 5 ci chamber and a 2 foot 12 ci barrel and a 3 gram paintball (the paintball can roll in the barrel but fits tight).

My only question that i ask myself is will it have enough power to propell the paintball at at least 300fps? A mini combustion is not very powerful, so i dont really know.(If it is not enough i will make a airsoft version).


Thank to reply.

no offence but I think that some designs lack practicality... (and most likely it will lack power)

how many cartridges can you build for it ??

20 ? maybe 50? so how much time will it take to build them and how much will it cost ??


I have enough problems with a pretty simple semiauto design shooting spherical ammo... what's the point in desigining guns that use cartridges ?

what's the point in desigining guns that use cartridges ?

I think that davidvaini will post soon...

Why do you ask me questions? I asked you! Do you know a way of calculating combustion power with the data that i provided?

I think that i will build like 5 catridges... and a magasine.

http://www.hogsden.net/images/gallery/c ... index.html

Making a cheytac is not impossible...

You would go mad trying to spray the right quantity of fuel in that size chamber. Syringe might be able to do it.

Compare to the size of the Tippmann C3 chamber/barrel which uses air and propane for up to 300fps.


This reminds me of the time I sketched up a preloaded hybrid cartridge for a rocket launcher many moons ago.

http://www.spudfiles.com/forums/hybrid- ... t6559.html

Two bits of pipe, two endcaps and it's a launcher of mass deafening with enough muzzle blast to roast a small chicken.

that would not be so difficult, you would just have to seek out the best practicability. Make a large container at whatever mix you want, and just fill the cartridges with it. I'd go for a hybrid cartridge type, but that's just me.
You can make your cartridges in copper tubing, epoxy on the end, with a schrader and a nail (electrodes + injection); fill you cartridge with the premade mix, be sure to over fuel it as you want the mix to fill all the volume, and then stick the paintball in it. you'd have sturdy cartridges, re-usable, hybrid capable while implementing a burst disc behind the paintball.

I think it's a great idea. And i think you should try and make a prototype.

Do you know a way of calculating combustion power with the data that I provided?

use HGDT

lol sorry but I thought you wanted to build a semi...

I am just warning you that it won't be very powerful and getting the right mix will be a PITA with such small volumes...

keep in mind that problems with metering wil cause lack of consistency. This in turn, will have a negative effect on accuracy...

If I were you I would save some cash and buy a compressor

EDIT
what's the ID of 3/4" SDR pipe ?? I tried to get 5 c in chmber volume but even when I entered 3/4" HGDT showed that the cartridges have to be longer than 11 inches

I think it's a great idea. And i think you should try and make a prototype.

YAY! finally the message that i was seeking over for 1 year!

I got in mind a magasine and shell ejecting system that would be very practical( pull bolt back, pull it forward) with a magnet as a catridge catcher.

Compare to the size of the Tippmann C3 chamber/barrel which uses air and propane for up to 300fps.

I tought of that too but i forgot to post it, i hope that poland spud and its optimism is wrong...

EDIT: Poland posted before me and yes, i will use a metering system(probably a syringe) and butane.

If my experiments are anything to go by, you're going to need a much larger cartridge than that, with a wider diameter than the barrel, unless you're using a hybrid rather than combustion cartridge.

I think that because your cartridge is so small, manually spraying the hairspray in will result in way too much fuel, not nearly enough air. I have always thought about this type of cartridge, but after building a combustion marshmellow gun with with a quite a small chamber (was like 1.5-2" x 10" i think) I wasn't even going to bother.

However, this has got me thinking, If you've every looked at the tank in a refillable lighter, there is a small one way valve that lets you refuel it. If you care to try it, you might cut that out and glue it somewhere on your cartridge. This way, you could easily fuel the cartridges and the amount you put in will be significantly easier to control that a regular hairspray canister.

Also, you could try hybrid cartridges. I don't know if it will work, but you could -as well as the lighter one way valves- install a shrader (bike tyre) valve as well then manually pump air in with a bike pump. I'm not talking heaps of pressure, but if you experiment you might find the right fuel/air ratio. Again, I have no idea how effective this would be, probably very time consuming to load each round too.

Hey guys did any of you actually read my post?

Metering wont be difficult, he makes the propane/butane/whatever + air/O2 mix in a larger container, an then fills the small cartridges with it! Simple, effective, and if the reservoir is steel, i think _Fnord made some interesting testing about confined deflagration. So it's pretty safe too.

Demon, you got to think of hybrid cartridges, a simple combustion wont give you anyhting good.

I will make bigger catridges, 1 inche ones and 4 inches long. with the one that i had previously, hgdt told me the i was going to be 300 fps, what i aim for but now hgdt tells me "capacitance overloaded"(french traduction) and i cant try my new catridge, wich will make my gun bigger because the catridge holder will have to be 1 1/4 inches.

Can someone tell me what will i get with hgdt? wine has some problems...
specs: 1 inch chamber 4 inches long and .7 barrel and ammo and 3grams/.1 oz for the ammo(paintball) put barrel lenght to best lenght you can( by looking at the chart)