I agree with 2holer. Much of that weight reduction seems to be in the very thin barrels. I have 2-20 ga. Flues, and a 16 ga. Flues which I bought very cheaply as parts guns. All have badly split barrels in the forearm area, and the split areas are quite thin. I don't know if any bore obstruction was involved in these. I assume there was at least a little plug of snow. A friend's younger brother used to shoot 20 ga, 3" magnums out of his Dad's flues and still has his fingers. Well... all but one, but that was another story.
