Yeah, it's Vietnam. Hello people. The soldiers were driven to do way more fucked up things than smoke pot out of a shotgun. Not only that, but did anyone stop to consider that it's just as dangerous going to war while stoned? When you know that you will be handling a loaded firearm and there will be people shooting at you and trying to kill you? When you are in such a fucked up situation, you try to find ways to forget and entertain yourself. I personally wouldn't do this, but the fact that these guys did it doesn't bother me a bit.