As an outsider looking in I would put up another argument, without the right to bare arms you would not have the other freedoms under the constitution you do now.
You can look at the UK as an example of how governments erode rights you though were set in stone, do you really think we have "Free speech" or is it just what we are allowed to say, we are the most government monitored country in the world (And that includes all the totalitarian ones) "For our own safety", we now have to ask permission to demonstrate and are told when and where we may or may not do it.
Our laws have been removed, corrupted, or watered down to the point that the rich hold all the cards in courts that have become fat cat clubs using the police as enforcers*.
The uproar from your anti gun lobby whenever there is a shooting is made nonsense by one simple fact, most if not all these mass shooting take place where the strictest gun controls are, in other words all they have done is created a safe space for the shooter.
Far from it being a threat of "Violent revolution" its a warning that those rights having been paid for in blood will be defended.
*The police were created to protect the public yet are now little more than collecting agents for the DVLA (A private company), carry out forced repossessions on behalf of private financial institutions and enforce an ever growing list of government dictates.
