I would remind them about the American assistance tot he French resistance in Nazi occupied France. The Americans dropped single shot .45 cal pistols with 5 rounds of ammo out of planes all over the countryside. In addition to the ammo there was a note; "Take this gun and get another."
If things got real bad, I'm pretty sure there are enough implements of death to get more guns real quick if need be. So, I don't really sweat the gun grabbers.