If I recall, the AK-47 had an interesting role in a trilogy of time traveling books.
http://en.wikipedia.org/wiki/Weapons_of_choice
In the books, a near future (near our present) naval task force accidentally travels back in time to WWII. The U.S. eager to get a leg up in the war asks the chrononauts to give them future tech. The only problem is that WWII American doesn't have the manufacturing technology to produce any of the current equipment. So the chrononauts dig through their archives and find plans for the AK-47, which, as it turns out, is manufacturable in early 1940's U.S. thereby giving the Americans a weapon from the future, but still old enough that they could be produced in bulk.