When someone repeatedly threatens to kill you it's not extreme.  If they were just arguing I would agree.  This is the problem, people defend the rights of crazy or irresponsible people to have firearms or forearms and it brings the rest of us down with them.  If he threatened me like that I would have a restraining order for documentation purposes, and would not confront him.  Part of the job of the police is to prevent escalation in situations like this.  If you threaten to kill people, not just have firearms for protection, then you are a risk to society.  I don't believe in protecting these peoples rights, because if the crazy guy was killed, then the other guy would be looking a charges.  That happens all the time.  If you really think you have the right to defend yourself and your property without recourse afterwards, you are mistaken.  We have laws, but as shown in recent years, they are not always followed, and not always protecting you like you think.