Dick's Sporting Goods, the nation's largest sporting goods retailer, will stop selling assault-style weapons like the one used in the Parkland, Florida, high school shooting.

The company said it will also raise the minimum age for all gun sales to 21. Dick's (DKS) will not sell high-capacity magazines that allow shooters to fire far more rounds than traditional weapons without reloading, as well as other accessories used with weapons similar to the AR-15.

The company expects criticism from gun rights advocates as well a hit to sales, Dick's CEO Edward Stack said on CNN's "New Day."

"The hunt business is an important part of the business, no doubt about it. And we know there will be some backlash," he said.

But he said he and other executives at the company were moved by the Parkland school shooting survivors' push for gun control measures.

"As we sat and talked about it with our management team, it was -- to a person -- that this is what we need to do," he said. "These kids talk about enough is enough. We concluded if these kids are brave enough to organize and do what they're doing, we should be brave enough to take this stand."

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The Parkland shooter, Nikolas Cruz, did buy a gun at Dick's, but the company said it wasn't the AR-15-style rifle that he used in the school shooting. But Stack said when the company learned about that sale "we had a pit in our stomach."

"We don't want to be a part of this story any longer," he said.

The company stopped selling those military-style semiautomatic weapons in its Dick's-branded stores after the Sandy Hook elementary school shooting in 2012, but they were still available at its 35 Field and Stream stores.

Now it will pull those weapons from all of its stores.

But Dick's move won't do much to slow down sales of assault-style rifles or other firearms, experts say.

The reason: there are about 56,000 licensed firearm dealers nationwide, many of them single location mom-and-pop type stores. Cruz legally bought the weapon he used in the Parkland shooting at such a store, Sunrise Tactical Supply, in Coral Springs, Florida, about a year ago.

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These mom-and-pop stores handle a significant percentage of sales of overall gun sales, perhaps even a majority, says Brian Rafn, the director of research at Morgan Dempsey Capital Management, but hard statistics on market share are not available. Dick's and other major retailers sell very few assault-style rifles, he added.

For example, Walmart (WMT), the nation's largest retailer and a major seller of firearms, announced it would stop selling the military-style semiautomatic weapons in August 2015. But the company's decision "didn't put a dent in the market, Rafn said. "With 56,000 storefronts selling guns, a few guns here or there at Dick's isn't going to make a difference."

On Wednesday, Walmart announced it would also raise the age restriction for purchase of firearms and ammunition to 21. It was also "removing items from our website resembling assault-style rifles, including nonlethal airsoft guns and toys."

Semiautomatic rifles will still be available at outdoor sporting specialty retailers such as Cabela's and Bass Pro Shops, which recently merged, and Gander Outdoors, which was recently purchased by Camping World (CWH). Neither Bass Pro Shops nor Camping World responded to a request for comment on Dick's action.

Dick's, which has 852 stores, does not break out how much revenue or profit it gets from firearm sales. Unlike many other traditional retailers, it is adding -- rather than closing -- stores.

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"We support and respect the Second Amendment, and we recognize and appreciate that the vast majority of gun owners in this country are responsible, law-abiding citizens," he said in a letter released Wednesday. "But we have to help solve the problem that's in front of us."

Stack, 63, is the son of the chain's father. He has been CEO for 34 years.

National Shooting Sports Foundation spokesman Michael Bazinet said he is "disappointed" in Dick's.

"We respect the right of all companies to make the decisions they believe are appropriate for their business," he said. "Nonetheless, we are disappointed by the decision of Dick's Sporting Goods to stop selling modern sporting rifles ... to cease sales of certain magazines and to raise the purchase age to 21 for firearms at all its stores."

Stack also called for a nationwide ban on bump stocks, which allow semi-automatic weapons to fire as if they are automatic weapons. Dick's said it has never sold bump stocks.

Stack also urged Congress to sign into law the age restrictions his company has put in place, along with tougher background checks on all gun sales.

"Some will say these steps can't guarantee tragedies like Parkland will never happen again. They may be correct -- but if common sense reform is enacted and even one life is saved, it will have been worth it," he said in the letter.

-- CNN's Kate Trafecante and CNNMoney's Aaron Smith contributed to this report.