Just watched a compare/contrast kinda thing on the Military Channel with the M-16 and the AK-47.
One of the things specifically mentioned was performance in Vietnam.
The AK-47, constructed of heavier wood and metal parts could and often was used as a clubbing/striking weapon at close range with little damage done to the weapon.
The M-16, which was constucted in great parts of composites--was said to "break" when used in a similar fashion.
The Russians, the Vietnamese, and former US troops all more or less agreed about that.