Which is a better gun maker? Russia or the United States?

My friend and I were talking about guns and he told me that the United states has a rich history in gun making. There are a lot of breakthroughs in gun making that were American. However, it is widely regarded, though debatable, that it was the Kalashnikov that won the Vietnam for the communists. So basically, it was Russia's AK47 vs USA's M16. Is this a case of one gun to rule them all or was the AK47 just a fluke?