“Of all the weapons in the vast Soviet arsenal nothing was more profitable than Avtomat Kalashnikova model of 1947, more commonly known as the AK-47, or Kalashnikov. It’s the world’s most popular assault rifle, a weapon all fighters love. An elegantly simple nine pound amalgamation of forged steel and plywood, it doesn’t break, jam, or overheat. It will shoot whether it’s covered in mud or filled with sand. It’s so easy even a child could use it, and they do.”
~ Yuri Orlov
Lord of War
That's what got me interested in building an AK, almost 20 years ago: saw a video of some guy with an AMD65 parts gun, filling the thing up with sand, and firing it. Even with all of that crap inside, it still worked (mostly ;^)...