The gas tube is supposed to get hot. Ten rounds is about right-- depending weather conditions it can actually happen within 5 rounds.
That gas tube is ported directly from the barrel. The hot gas from each fired round adds more and more heat to the tube. It doesn't take much for the "hand guard" to get too hot for handling either. If you fire at a quick enough pace, you will often see beads of cosmoline begin to sweat out of the hand guard, and sometimes even the stock for end. And if you keep it going, burnt cosmoline smoke will start to rise off the hand guard too.
That gas tube is ported directly from the barrel. The hot gas from each fired round adds more and more heat to the tube. It doesn't take much for the "hand guard" to get too hot for handling either. If you fire at a quick enough pace, you will often see beads of cosmoline begin to sweat out of the hand guard, and sometimes even the stock for end. And if you keep it going, burnt cosmoline smoke will start to rise off the hand guard too.

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