Devil Hunter CO2 mod

Introduction
The Devil Hunter mod, named after its creator1, is a mod to make GHK M4 and AK green gas magazines capable of being charged with liquid CO2 by reinforcing the seal of the internal gas tubes and replacing the valves.

Needed things

 * GHK CO2 Output valve
 * KJW M9 Fill valve
 * Teflon tape
 * Valve key

Instructions

 * 1) Disassemble the magazine and remove the innards from the shell.
 * 2) Unscrew the two gas tubes and the caps and inspect the O-rings for wear or oxygen damage/cracks. Replace if worn or deformed.
 * 3) Reinstall the gas tubes with teflon tape on the threads of the tubes and the end caps.
 * 4) Unscrew the original green gas output valve and install the CO2 valve, make sure there are no old O-rings or gaskets in the chamber that would prevent the output valve from seating correctly.
 * 5) Unscrew the original fill valve and replace it with the KJW M9 valve.

Fill adapters
There are plenty of adapters that can be used depending on your of CO2 fill source, many of them thread on to .825x14 NGO threads (paintball tank standard), for instance the MadBull XM (XC01).

If you want to use a Soda Stream bottles or similar cartridges you will need a thread adapter as they are manufactured W21.8 threads. The adapter should be female W21.8 to male .825x14 NGO. (Don't forget O-rings when stacking adapters!)