CatgutViolin does a very quick test of the Viper Tech Colt 727 Gas Blowback Rifle in the snow if it is possible to skirmish with it given the issues with gas blowbacks in cold weather conditions... "Viper Tech (or Vipertech) airsoft rendition of a Colt 727, using a VT soft hammer spring and WA buffer spring. The magazine is a GHK stanag, filled with propane. The whole gun was left in the snow for an hour before testing."