Shares of U.S.-based gunmakers Sturm, Ruger & Co. (RGR – Free Report) and American Outdoor Brands (AOBC – Free Report) dipped in morning trading Wednesday after Dick’s Sporting Goods (DKS – Free Report) announced that it will discontinue the sale of assault-style rifles at its stores.

The sporting goods retailer said Wednesday that the company was “deeply disturbed” by the recent mass shooting at Marjory Stoneman Douglas High School in Parkland, Florida that left 17 people dead. Authorities have said that the gunman used a legally-purchased AR-15 rifle during the attack.

“Thoughts and prayers are not enough,” said Dick’s CEO Edward Stack in a statement. “We will no longer sell assault-style rifles, also referred to as modern sporting rifles. We had already removed them from all Dick’s stores after the Sandy Hook massacre, but we will now remove them from sale at all 35 Field & Stream stores.”

Stack also announced that Dick’s will no longer be selling high-capacity magazines or any firearms to persons under the age of 21. The chief executive later urged regulators to follow suit, recommending a nation-wide ban on assault-style rifles and a higher minimum age for gun ownership.

“Some will say these steps can’t guarantee tragedies like Parkland will never happen again,” said Stack. “They may be correct—but if common sense reform is enacted and even one life is saved, it will have been worth it.”

Shares of American Outdoor Brands—formerly Smith & Wesson—fell about 2.5% to touch an intraday low of $9.03 in early trading Wednesday. The historic gunmaker has now shed more than 50% of its value over the past year. Meanwhile, Sturm, Ruger & Co. dipped as much as 4% in morning trading and is now down more than 11% within the last year.