The story about the AK-47 in the mud probably came from "About Face: The Odyssey of an American Warrior" by Colonel David H. Hackworth. If I remember correctly, they found a dead VC in the mud. The body had obviously been there some weeks. Colonel Hackworth said something like "You guys want to see a real assault rifle?", picked it up and fired it.
If you haven't read the book, you should. "Warrior" is absolutely correct!
If you haven't read the book, you should. "Warrior" is absolutely correct!