Walmart will stop selling ammunition for assault-style weapons and no longer allow customers to openly carry firearms, after separate shootings at company stores last month left 24 people dead. The retailer will also complete its exit from the handgun market by ending sales in Alaska.

The decision by the nation’s largest retailer reflects a sweeping shift in how American corporations approach gun control, according to analysts and communications experts. Walmart, which is based in Bentonville, Arkansas, made its fortune selling low-priced goods in Red State America. But as the country faces one mass shooting after another, executives said it was time to make a stand, even if that meant angering some of its most loyal customers.

“In a complex situation lacking a simple solution, we are trying to take constructive steps to reduce the risk that events like these will happen again,” chief executive Doug McMillon said in a memo to employees on Tuesday. “The status quo is unacceptable.”

Walmart says it will stop selling ammunition for handguns and short-barrel rifles – including .223 caliber and 5.56 caliber cartridges, which can be used in military-style weapons – once it sells through its current inventory. Those changes are projected to shave Walmart’s market share of ammunition sales from about 20% to as little as 6%, the company said.

“This is a major move. The sheer size and power of Walmart means this is perhaps the biggest blow to the NRA in the history of the organization,” said Chris Allieri, a crisis management expert and founder of Mulberry & Astor, a public relations firm in New York. “This is not some left-leaning, coastal CEO sending a tweet or two. This is Walmart saying. ‘This is how we’re going to do business going forward. Take note.’ ”

The National Rifle Association did not immediately respond to a request for comment.

Walmart, which sells guns in about half of its 4,750 U.S. stores, will continue selling long-barrel deer rifles and shot guns, as well as other firearms and ammunition for hunting and sports shooting, McMillon said. It will also continue to allow customers to carry concealed firearms at Walmart and Sam’s Club store, as long as they have proper permits.

The decision comes after mounting pressure from gun-control advocacy groups, politicians and Walmart’s own employees. About 40 white-collar workers in California walked off the job last month to protest its gun policies. E-commerce workers in Portland, Oregon, and Brooklyn also urged the company to stop selling firearms and organized a Change.org petition. As of Tuesday afternoon, it had more than 142,000 signatures.

The protests followed a mass shooting in El Paso, Texas, that killed 22 people and wounded dozens of others. Days earlier, two Walmart employees were fatally shot at a store in Southaven, Mississippi, and a former employee has been charged in the shooting.

Walmart has tightened its gun policies over the years. It stopped selling handguns in every state but Alaska in 1993 and phased out assault-style rifles in 2015. Last year, it raised the minimum age for gun purchases from 18 to 21, two weeks after 17 students and teachers were killed in a shooting at a high school in Parkland, Florida.

McMillon, who is a gun owner, said the company is also calling on President Donald Trump and members of Congress to advance “common sense measures,” like more stringent background checks.

Gun control advocacy groups like Everytown for Gun Safety applauded the retailer’s decision, and said it reflected a changing reality in which 94% of Americans support universal background checks, and 61 percent favor of tighter gun laws, according to a May poll by Quinnipiac University.

“As the largest brick-and-mortar retailer in the country, Walmart has its finger on the pulse of what Americans want,” said John Feinblatt, president of Everytown for Gun Safety. “This decision reflects a clear reality – Americans want to be kept safe from gun violence.”

In prohibiting the open carry of firearms, Walmart joins a number of other big-name retailers, including Target, Starbucks and Chipotle.

Dick’s Sporting Goods overhauled its gun sales policies last year after the Parkland shooting. Gun reform became a particular issue for chief executive Ed Stack, who became even more concerned about firearms policies after learning the man who shot up a high school had once purchased a shotgun from a Dick’s store.

A few weeks after the rampage, Stack announced that Dick’s was pulling all assault-style weapons from its stores and banning high-capacity magazines and “bump stocks” that could effectively convert semiautomatic weapons into machine guns. Stack also announced that Dick’s would not sell firearms to people younger than 21.

Dick’s has never disclosed what share of its sales come from guns alone. Still, the company Dick’s has continued to reevaluate its hunting business. In a 2018 pilot program, the company took all guns out of 10 stores and filled the empty space with products targeted for those markets, like sports team merchandise. Those 10 stores outperformed the rest of the chain and have continued to deliver, executives have said.

In March, Dick’s removed all guns from 125 of its roughly 730 stores. Stack told The Washington Post earlier this year that the company would consider whether to expand that roster based on how those locations performed. In a company earnings call last month, Dick’s President Lauren Hobart said it was too soon to gauge the strategy’s success.