Walmart got it right when it announced early September, following the mass murder of 22 people at one of its El Paso stores, that it would cease selling ammunition for all handguns and military-style weapons. It was the corporation’s way of saying getting the guns is not the answer.

The truth is, the guns can’t be gotten. I’ve seen that in Connecticut, a state known for stringent gun laws. Several months before the 2012 tragedy in Newtown, I happened to be in Stamford, Conn., police headquarters. Taped to a wall was a flier announcing the city’s latest antigun campaign, requesting that citizens voluntarily turn in their firearms.

“How many guns have you collected?” I asked the officer on duty.

“About 75.” It was more than he’d expected, he said.

According to that officer, and my Congressman U.S. Rep. Jim Himes, none of the near-useless weapons turned in was illegal. And that’s the fundamental problem. It’s difficult to convince legal gun owners to part with a viable weapon. What hope is there that a criminal, or a gun owner who is mentally unfit, will voluntarily surrender one?

The illicit firearms on the streets are staying there, and their number is staggering. In 2018, in Chicago alone, police confiscated more than 9,600, an average of more than one an hour. And still, the Chicago Tribune reports, there have been more than 2,300 city shootings in this calendar year.

The most expedient method of removing firearms from those who shouldn’t have them would be to pass federal legislation making confiscation mandatory — as Australia did, following a spate of mass killings that culminated in a 1996 nightclub massacre that took 35 lives. Twelve days later, the nation enacted strict gun reform legislation that limited the types of firearms available to civilians. The government has since collected and destroyed more than a million weapons through buyback and amnesty programs. Over the next 20 years, Australia suffered not a single fatal mass shooting.

Gun policy experts say that strategy wouldn’t work here. “The U.S. gives too much power to single-issue lobbies,” explained David Hemenway, a Harvard professor of health policy, referring to the influence of the National Rifle Association.

A better solution would be to render illicit firearms useless — not as insurmountable as it might appear.

Today, one can walk into a gun shop and purchase, for instance, a .22, .38, or .44-caliber handgun. Most firearms are built to accommodate one size round only. So here’s what would happen if the manufacture of today’s standard-size rounds were outlawed, and .23, .39 and .46-caliber rounds took their place: Eventually, gun owners would run out of the old ammo, and their weapons would become paperweights.

We’d have the opportunity for a national gun policy do-over. New, tougher gun registration and ownership policies, some already favored by NRA membership, would be enacted in line with the changeover in rounds calibration. Attention could be paid to newer, research-vetted strategies, such as the universal adoption of smart-gun technology and limiting the size of rounds available to civilians. (Police and military would keep their current firearms and ammunition, manufactured and distributed under strictest control.)

To use the recalibrated rounds, people would have to purchase new weapons to fire them. Many would object. Why should a law-abiding citizen spend hundreds, perhaps thousands of dollars to replace one’s gun collection?

One answer: Gun manufacturers could offer a six-month window for any person eligible to turn in their old weapons and receive a partial rebate toward the purchase of new ones. For manufacturers and retailers, these sales would amount to a windfall of epic proportions.

Jesse Jannetta, a senior policy fellow for the Urban Institute, said such a plan “might have a substantial impact on mass shootings.” As for street violence, he added, “A lot of that is about the circulation of illegal guns, so maybe it would have a lot of impact there, also.”

Let’s not be naive. The gun policy experts with whom I spoke cautioned that this would not prove an overnight solution, that it might take a decade to fully feel its impact. And yes, they added, a black market for the old ammo would quickly develop. But they also agreed it was time for action.

A democracy sometimes requires that we sacrifice convenience for the public good. Passing through airport security is a hassle, but we accept it to help keep us safe. So would this proposal. Law-abiding citizens could still own guns. And that is all the second amendment promises. It does not prohibit federal or state governments from regulating the type of weapon one may own.

Ron Berler is the author of Raising the Curve: A Year Inside One of America’s 45,000* Failing Public Schools. A version of this piece first appeared in the Hartford Courant.