In Australia, in 1996, a man killed 35 people in the course of an afternoon rampage. Australia soon went from having relaxed gun laws to having tough gun laws, including such common-sense measures as character witnesses for people who want to own a gun, and the purchase of a safebolted to the wall or floor. There are still plenty of hunters in Australia, but it hasn’t had a mass killing since.

South Africa may be an even better example. For many years, South Africa was a country every bit as gun-soaked as America. I have a friend, Greg Frank, a hedge fund manager in Charlottesville, Va., who lived in Johannesburg during a time when it had become so crime-ridden that people felt the need to own guns to protect themselves. He, too, owned a gun as a young man: “I made the excuse that I needed it for self-protection.”

The guns didn’t make anybody safer. People who were held up while waiting at a red light rarely had time to pull out their guns. And the fact that so many homes had guns became an incentive for criminals, who would break in, hold the family hostage, and then order that the safe with the guns be opened. “Everyone knew someone who had family or friends who had experienced gun violence,” he said.

Finally, he says, people got fed up. In 2004, the laws changed, requiring annual relicensing, character witnesses and other measure to keep guns out of the wrong hands. There was also an appeal to voluntarily surrender guns.

“I took my gun to the police station,” recalls Frank. “The cop receiving it wrote down the serial number, took my ID, and I was gone. It felt transformational, like a huge weight off my shoulders.”