Ban "all" rapid fire / high capacity weapons. "All" meaning past, present and future. All Americans should pay, so allocate 100 billion for a buy back program (provides for $400 for 200,000,000 guns), and allocate 5 billion dollars to provide trigger locks for all the 300,000,000 guns that currently exist in American hands. Ensure all future gun sales include trigger locks.
Amend the constitution and include licensing / safety training for all gun owners. Strictly enforce laws where guns are used outside the law.
People do have the right to protect themselves. However, they can easily do that with single action pistols and pump shotguns with 5 or 6 rounds.
Americans can't buy grenades, bombs, missiles, tanks, nukes. Why should they be able to buy military level assault weapons?