Gun confiscation is not happening in the United States any time soon. But let’s suppose it did. How would it work? Australia’s program netted, at the low end, 650,000 guns, and at the high end, a million. That was approximately a fifth to a third of Australian firearms. There are about as many guns in America as there are people: 310 million of both in 2009. A fifth to a third would be between 60 and 105 million guns. To achieve in America what was done in Australia, in other words, the government would have to confiscate as many as 105 million firearms. And an American mandatory gun-confiscation program — in addition to being unconstitutional — would be extraordinarily coercive, and perhaps even violent. There is no other way around it: The mandatory confiscation of the American citizenry’s guns would involve tens of thousands of heavily armed federal agents going door-to-door to demand of millions of Americans that they surrender their guns. That. Is. Not. Going. To. Happen. If the president and gun-control activists want to keep saying “Australia” in response to every shooting in America, they should at least be honest about what exactly they are proposing.