“Or they just don’t work.”
The Russians used a lot of “homemade shit” to defeat the Germans in WW II. Russians are a brilliant people who have been traumatized by history and geography. If they want something to work they can make it work as well as to be maintained, serviced, and used by any random drunken peasant.
They kept their guns oiled while the germans guns failed from the Russian cold. Hitler was an idiot.