co2 adapter problems

[c11man]

I am looking to make a high pressure piston gun a i want to use co2 to get these pressures. I am looking for around 250psi in an all coper gun. I found a adaptor on BCARMS for 12gram co2 cartridges that goes to a schroeder valve. the only problem is that i am afraid that a schroeder valve will not be able to hold that kind of pressure because the one on bcarms is only rated to 160psi. Please tell me if it will hold the pressure and if not were could i get a better schroeder valve or a VERY simple mod for the valve because i have very limited tools. I neither is available could you post a place to get an adapter and valve setup that would work
thanks alot.

[john bunsenburner]

Dont worry sharders hold alot of pressure, up to 600-700psi. I have used mine upto 500psi without a problem.

[c11man]

thanks alot

did you have to mod yours at all?

[cheeseboy]

no modding is required for schrader valves take a look at this thread:
http://www.spudfiles.com/forums/viewtop ... tml#214755
Gippeto took one to 10000PSI and it still didn't fail, and make sure you get the chamber size right because the pressure in a 12g CO2 cartridge is around 600PSI so you need a chamber 2.4 times the size of the 12g Cartridge for it to be at that pressure, can someone please correct me if my numbers are wrong?

off topic but... are you by any chance ckman as your name is c11man and k is the 11th letter of the alphabet?

[Hailfire753]

liquid C02 expands. Much more than 2.4 time the size.

[john bunsenburner]

No hail what he is saying is that if you have 12grams of liquid CO2(1600g/l so 7.5cm cubed) you need a volume 2.4 times that size(18cm cubed) to get the pressure wanted(which i dont know) when using the whole cartidge. I am not sure if you answer is correct as density varies with pressure and so i leave it up to the others to find if the answer is correct(at standard pressure the calculation is wrong as there is only 11g of CO2 gas but at higher pressure the gas will be more dense ergo there will be more weight on less space).

[c11man]

thanks for all the help

i in no way wanted my name to be like ckman
i didnt even know that he egsited until last week so it is just a coinsidece