Bolt Action Rifle run on Propane

[spudnutbutthut]

Hey everyone, I have made a pretty successful C02 bazooka that runs on propane, with a leveled out bottle of gas it takes about 2 minutes to get to 45psi and then fires nerf vortexes like a champ. I want to try something new now, but im not very good with the tolerances of pressures, how to create perfect pressure and chamber to barrel ratio etc.

I have a few questions:

If I want to fire a .3g BB at 45 psi, to get to about 450-500 fps, what size chamber do I need? The barrel will be about 455 mm long with a 6mm diameter (inner), what would be an optimal ratio of chamber to barrel, please note I want to use a 3/4in sprinkler valve with blowgun. Unless there is a better way to make this. Im a bit of a noob so i need either some help or a link or two, cause all i see is 700psi cannons that fire metal ball bearings! OUCH!

Also how might a have a constant connection directly from the tank, but still be able to regulate the pressure without venting?

[jackssmirkingrevenge]

all I see is 700psi cannons that fire metal ball bearings! OUCH!

It's called "progress"

As to your requirements, a sprinkler valve is probably overkill. Blowguns alone can give pretty good performance though since you're using such low pressure, you're probably better off with a 1/8" or 1/4" Quick Exhaust Valve, with a momentary pilot that will give you good semi-auto performance.

[iknowmy3tables]

why is it called a CO2 bazooka if it runs on propane?

[spudnutbutthut]

LOL!, i dunno why i put Co2 in there. Could you maybe post an example of what jack described?

[clemsonguy1125]

Heres an example
http://www.spudfiles.com/forums/the-1-4 ... 20693.html

[spudnutbutthut]

hmmm, im bad at visualizing, what would be a good piston to use ? I want to make it bolt action so, a coax? I heard there was something bad about coaxials...hmmm, i just want whatever will be most accurate with a velocity around 450fps, is there anyway to use a program to determine speed of projectile with the chamber size and pressure, barrel size etc?

[jackssmirkingrevenge]

is there anyway to use a program to determine speed of projectile with the chamber size and pressure, barrel size etc?

Have a play with Gas Gun Design Tool

I want to make it bolt action so, a coax?

Not a good idea for bolt action as the section of the barrel where the bolt should be will be enclosed in the chamber.

One of these and you're sorted

[spudnutbutthut]

cool, but how would i use a QEV? I have 0 clue about pistons and how to make one even though ive researched lol, and no idea how to use anythin cept ball and sprinkler valves

[Gun Freak]

Apparently you haven't researched... there is like a thousand threads on piston valves.

[Technician1002]

Start in the Wiki. It has a section on piston valves.

http://www.spudfiles.com/spud_wiki/inde ... ston_valve

[Crna Legija]

this should help