Amazing design he came up with. My dad is a gun collector, and I've been around the semi-auto AK since I was a kid.
Simplicity is its own beauty, as the saying goes, and the AK proves it. You can make them in a simple sheet metal shop if you know how. You can bury them in the Siberian tundra, dig it up weeks later and pop a magazine in, and that thing will fire. Desert sand, jungle muck, still works. And of course, that's born from lessons learned by the Soviets in the German invasion a few years prior to the design- make it simple, make it reliable, and make a whole bucket-load of them.
Kudos to Kalashnikov for one of histories' most recognizable and effective weapons, one that has literally changed the world.