I have used this KWC Colt National Match with good 40-50 mags of propane, it has not yet broken on me, and when I took it apart, everything looked fine. Gun was cleaned well and lubricated and then tested with duster gas.
I prefer duster for this gun because I think it was built for that type of gas, reason being is that it simulates actual gun fire by releasing a visible stream of gas from the hammer and the chamber area when the trigger is pulled. I find this extremely cool, because this is not possible with propane. I don't know if other ABS guns do this with duster gas aswell, but it's my 1st ABS GBB I ever owned and I love it.
Anybody else on here has 1 like this?
HFC134a = 350fps @ 23C
Propane = 390fps+ @ 23C
future mods: custom metal slide, high flow valve, ported barrel, custom grips