After current inventory is sold, the company will discontinue sales of handgun ammunition and short-barrel rifle ammunition such as the.223 caliber and 5.56 caliber.
The largest USA arms retailer also said it would discontinue handgun sales in Alaska, the only state where it sells these guns. "The store said it will gear its focus toward long barrel deer rifles and shotguns, supply much of the ammunition they require and provide hunting and sporting accessories and apparel". "We should not allow that to happen", McMillon said in a statement.
Walmart will stop selling handguns and certain types of ammunition, and will no longer allow customers to openly carry firearms.
A Walmart spokesman did not immediately respond to a question about what stores would do if a customer defied the company's request not to openly carry a gun.
The company's latest measures come after a man with an assault rifle killed 22 people at a Walmart in El Paso, Texas, on August 3, just days after a Walmart employee in Southaven, Miss., fatally shot two co-workers.
The changes come after two shootings in the southern United States.
Last month Walmart disclosed that it accounts for about 2 per cent of the USA firearms market, which would place it outside the top three sellers. "We believe it will likely drift toward the lower end of that range, over time, given the combination of these changes".
McMillion, who said he was a gun owner himself, took pains to avoid alienating customers.
He says Walmart will continue to treat "law-abiding customers with respect" and it will have a "non-confrontational approach".
In addition, McMillon said that he would send letters to the White House and congressional leaders that "call for action" on "common sense" gun safety measures. He said, "Congress and the administration should act". "Given our decades of experience selling firearms, we are also offering to serve as a resource in the national debate on responsible gun sales".
In one well-publicized incident last month just days after the El Paso shooting, a man in Missouri was arrested after entering a Walmart wearing body armor and carrying a loaded military-style rifle.
The move comes amid increasing pressure on the company, often cited as the largest firearms seller in the US.
But Democratic presidential candidate Beto O'Rourke, who previously represented El Paso in Congress, called Walmart's move a "step in the right direction", adding, "we can't rely on corporations to stop gun violence".
There are 49 Walmart stores in MA, including 27 Supercenters.
Despite its history of selling hunting weapons that goes back to Walmart's origins, Walmart has shifted its gun policies.
Walmart stopped selling assault-style weapons in 2015 and raised the minimum age to buy firearms and ammunition to 21, from 18, in 2018. The company said Tuesday that it would explore sharing its proprietary gun-sales technology platform with other retailers.