The 2nd Amendment of the US Constitution was written in a bygone era and serves no purpose in modern society. However, the 2nd Amendment is frequently used as an excuse by people to stockpile munitions that serve no legitimate purpose in society.
Guns should be treated no differently that the privilige to operate a motor vehicle. You should need a license to carry, you need to meet criteria involving personal safety, safety of the public, etc.; and just like you cannot drive a tank down the street, automated weapons have no place outside of a police or military institution.
Keeping and bearing arms is not a human right. It is a privilige that should only be available to the extent that it serves a legitimate purpose in society.