The genie is long and truly out of the bottle. When someone realizes the implication of oval boring, we'll even have printable guns that leave no scoring on the bullet to identify the weapon it was fired from.
As desirable as it might be to better control who has access to guns, outlawing them will only benefit the global market in illegal weapons. Witness the success of the "War On Drugs", initiated by the Nixon administration and the greatest single factor in the ascent of Mexican drug cartels.
"Any excuse will serve a tyrant." -- Aesop