America's thriving gun industry, which has been riding high on a surge in sales, is under increasing pressure in the wake of Friday's elementary school massacre.

Responding to a national wave of revulsion over the 27 murders in Newtown, Conn., retail chain Dick's Sporting Goods Inc. on Tuesday suspended sales of semiautomatic rifles at its 480 stores, while Wal-Mart Stores Inc. deleted from its website a listing for one such rifle.

Private-equity firm Cerberus Capital Management LP said Tuesday it would try to sell Freedom Group Inc., the manufacturer of the Bushmaster rifle that police say Adam Lanza used in last week's shootings.

"We have to get control of this," said Larry Stone, a member of Dick's board, in an interview Tuesday. Mr. Stone said he fully supported the decision to remove the semiautomatic guns from Dick's shelves. "I hope other people follow suit," he said.

Shares of gun makers and some retailers have been affected. Smith & Wesson Holding Corp. , whose stock had nearly doubled this year, fell 10% on Tuesday to $7.79. Shares of Sturm, Ruger & Co. fell 7.8% to $40.60. Cabela's Inc., a big gun retailer, fell 6% for a second consecutive day; Dick's stock rose 2%.