Couldn't the lubrication used on that BAR have contributed to the jams?I always understood in extremely cold weather you need to use a dry lubricant.If that's the case and the wrong lubricant was used,the gun can't be held in fault.
The gas system was kept dry and unlubed as is recommended and a lubricant rated for well below the actual temperature was used on the rest of the gun.We live in a climate where the temperature often drops down to -20 degrees or colder during our late hunting seasons and we are very familiar with preparing our equipment for these cold temperatures.All of the people that I hunt with now use bolt actions.We degrease the firing pin assemblies and have never had a bolt gun fail to function due to climate conditions..