As a lifetime gun owner, former hunter, and army veteran, it is my opinion there is absolutely no reason that any US private citizen should be allowed to have, own, or use any weapon that has the capability of a magazine exceeding eight shells and with automatic firing capacity.
The only personnel that should be allowed to have, and use, these weapons are authorized, on-duty law or military active-duty personnel who are trained in the use of these weapons for the purpose of protecting the public welfare.
We are not under attack as a country and not have been since 1776. The U.S. Constitution (2nd Amendment, 1791) authorized the right of private citizens to own, use and bear arms. Assault weapons were not available until 1944.
I am not suggesting hunters should not have appropriate guns to legitimately hunt any lawful animal that is not an endangered species. No one needs an automatic weapon for hunting anything, assuming they can shoot accurately.
With regard to personal protection, that is what law enforcement and military is charged to do. Individual citizens do not have any need to own or use excessive-capacity automatic weapons for that purpose (National Rifle Association objections duly noted).