The majority of the guns received in a buy back would only result in the honest, law abiding citizens being unarmed while the dishonest and lawless ones maintain their guns to commit illegal acts.
Both concealed carry and open carry provides an extra layer of protection until first responders can arrive. Our first responders are extremely valuable assets and do an excellent job; but they cannot be everywhere in an instant. Crime rates tend to drop where there are more armed, law abiding citizens.