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Want to build co2 powered rifle.
Posted: Tue Jun 25, 2013 6:34 pm
by beastmode986
I haven't logged on in awhile but I plan on building a co2 powered air rifle. I am thinking of break line for one of the barrels but I am planning on using a basic qev with the air gun on the back. If I get one of these
http://www.ebay.com/itm/PAINTBALL-QUICK ... 3f25b798d5
Will it thread into a 1/2 galvanized pipe coupling? If I use a 6''-10'' piece of galvanized steel as the air chamber and then put on a coupling then the 12g co2 adapter will I run into any problems?
Thanks.
Posted: Tue Jun 25, 2013 10:52 pm
by grumpyoldman
I think the 12 gram cartridges are 3/8"-24 UNF. You would need a 3/8"-24 UNF adapter to 1/2"-14 NPT.
Posted: Wed Jun 26, 2013 7:50 am
by jackssmirkingrevenge
grumpyoldman wrote:I think the 12 gram cartridges are 3/8"-24 UNF. You would need a 3/8"-24 UNF adapter to 1/2"-14 NPT.
I think the means the thread that is meant to screw into where a paintball bottle normally goes.
I find this screws into 1/2" BSP well enough, not sure about NPT.
I threaded a paintball bottle into a 1/2" BSP ball valve
here. It won't seal without modification though, or thread tape...
Posted: Wed Jun 26, 2013 8:46 am
by grumpyoldman
jackssmirkingrevenge wrote:grumpyoldman wrote:I think the 12 gram cartridges are 3/8"-24 UNF. You would need a 3/8"-24 UNF adapter to 1/2"-14 NPT.
I think the means the thread that is meant to screw into where a paintball bottle normally goes.
I find this screws into 1/2" BSP well enough, not sure about NPT.
I threaded a paintball bottle into a 1/2" BSP ball valve
here. It won't seal without modification though, or thread tape...
Oh, in that case:
You can also use a 1/2" NPS (straight pipe thread) thread not NPT (tapered pipe thread). A paintball ASA thread is .825-14 NGO. A diagram is below.
1/2" BSP has the same thread diameter (thread major diameter: .825 inch) but a slightly different thread angle (55 degrees).
1/2" NPS has the same thread angle (60 degrees) but a slightly different thread diameter (thread major diameter: .826 inch).
Posted: Wed Jun 26, 2013 10:48 am
by beastmode986
Ok thanks a lot guys, I just found an on off asa that I had lying around! Basically my idea is to reduce the pipe down to 1/8'' then get an 1/8'' nipple and thread them together. Seems like this could be easier than hunting down some other type of pipe. One more question, there wont be an issue with regular galvanized pipe from Menards holding the pressure of a co2 cartridge right?
Posted: Fri Jun 28, 2013 12:13 pm
by Brian the brain
using a basic qev with the air gun on the back.
I sure hope you're not going to putl 850 psi on a blowgun..
Not only will it be impossible to press open...it will most likely burst...violently...
Posted: Mon Jul 01, 2013 12:42 pm
by beastmode986
I plan on using the 12 gram cartridges and giving the gas a little room to expand. Also, on my QEV will I have any issues filling it from the air chamber directly? I remember someone telling me awhile back that I need to poke a small hole in the piston/rubber piece in order to fill it either from the blowgun or the air chamber, which one is it? I have it all assembled and my co2 is coming in the mail so ill have a video up by the end of the week.
Posted: Mon Jul 01, 2013 1:00 pm
by Brian the brain
A "little"room won't cut it.
Check the 12 gram sticky!
And it was probably me telling you about the hole...
A small hole , between the flat center and the outer edge, will enable it to be pressurised from the chamber-side and reseat after piloting.
Don't puncture the sealingface itself!!!
A small spring will help the piston stay seated apon initial pressurisation.
Posted: Mon Jul 01, 2013 4:47 pm
by beastmode986
So a hole right where the outer edge and and flt center meet? I dont want to mess up lol
Posted: Sat Jul 06, 2013 3:29 pm
by choke
I was on the "how much co2" sticky, but couldn't get an answer. I've been kicking numbers round my head for a while now, and wondered if someone here could confirm. I'm filling a 1.5" dia x 12" long chamber to 120/150 psi. If I was using 2 12g disposables, I think I'll get 5 shots, before empty. Hope someone can put me out of my misery

Posted: Sat Jul 06, 2013 5:01 pm
by dewey-1
5 shots at 100psi for 2 CO2 12g is more realistic for your chamber size.
Posted: Sat Jul 06, 2013 7:05 pm
by choke
Thank you! That's changed the size of the supply to either a 4 or 9 oz tank, and a custom stock to suit. Thanks again!
