Why not just admit the Constitution doesn't mean squat and hasn't since 1861? No need to cherry pick one or two little things according to current fads. It was toast the second Chief Justice Tainey died and the last restraints on Lincoln's dictatorship and murder spree were removed, and it never recovered from the corruption of the Chase Court and the Grant administration.
Nobody is going to turn in 400 million guns, no matter how many laws and regulations are passed; it's a moot issue. Confiscation won't work either; open borders guarantee that tactic will fail, and both Parties favor floods of cheap docile labor, the more the better. It's a dead issue.