Registered Bolt vs Registered Receiver Uzis

Most of the transferrable Uzis in the US are not factory original guns, but rather semi autos that were converted and registered as machine guns in the US before 1986 (when such activity was legal). There were several different ways to do this, with the two main ones being the registered bolt route and the registered receiver route. Today we are looking at what these different methods were, and what someone looking to get an Uzi ought to know about them.