Ken 927 got another custom gun test online and he tests the Tokyo Marui M4A1 MWS Gas Blowback at low temperatures. This means that he put the gas magazine in refrigderator at -minus 18 degrees Celcius for 15 minutes though after taking out the magazine, the temperature on the magazine is 0 degrees. That's still cold enough to find out if there is an effect on the firing of the gas magazine.