I didn't just ask him, but I also asked another guy chairmanloa1911 who was the most recent person to use crazyncman's five-seven and even he said that the gun did not have problems while on green gas/propane when using it and he was the sixth person that the gun was sent to. I really want this gun but I keep on hearing about people having problems with it on green gas and I also hear about people who have ran it on green gas for 2+ years.