Gun stores are under intense pressure from the massive outcry against assault rifles after last week's massacre in Newtown, Connecticut.

Large stores are responding by either suspending sales or pulling ads of semiautomatic rifles similar to the one used by Adam Lanza last Friday at Sandy Hook elementary school that killed 20 children and six adults. Some smaller stores, though, are holding tight.

The sports retailer Dick's Sporting Goods (DKS) said it has suspended the sale of certain semiautomatic rifles from its 511 stores in 44 states "out of respect for the victims and their families." Dick's also said in a statement that it has removed all guns from its store near Newtown.

The retailer did not say if this is the first time it has taken such a measure, or how long the suspension will last. A search on the retailer's website on Tuesday for "modern sporting rifles," as the retailer calls them, led to a blank page.

Wal-Mart (WMT) took down a listing on its website Monday for a semiautomatic assault rifle from the same maker as the Bushmaster AR-15, that was used by Lanza. In July, James Holmes used a similar semiautomatic rifle at a movie theater in Aurora, Colorado, to kill 12 people and injure 58 others.

David Tovar, a Wal-Mart spokesman, said the Bushmaster gun was not for sale online and the web listing contained directions for the nearest store where it could be purchased. The ad was pulled because of sensitivity to the Newtown massacre, Tovar said.

Similar assault rifles, including the Bushmaster, continue to be available for sale at over 1,200 Wal-Mart stores where guns are sold.

"We have not made any changes to the assortment of guns we sell," Tovar said.

Related: After the massacre, gun industry faces uncertain future

In the past year, sales of guns at Wal-Mart have skyrocketed. Executive vice president Duncan Mac Naughton told shareholders at a meeting in October that gun sales at Wal-Mart stores open for a year or more increased 76% for the year, and ammunition sales were up 30%.

While big retailers are making some changes, smaller gun stores aren't budging.

Timothy Smith, owner of Tim's Gun and Range in Winter Haven, Florida, said his store hasn't stopped selling Bushmaster guns and has no plans to.

"What happened at that school was a tragedy, but it wasn't the gun that did it," he said. "To change what we sell because of that wouldn't make sense."

An employee at Fernwood Firearms in Hankins, New York, also said the store will not make any changes.

Related: NRA laid groundwork against new gun laws

The killing also prompted a decision by New York's Westchester County against renewing a contract to host an annual gun show in February.

"The shows in past years were popular and run in a thoroughly professional manner. But at this time...a contract renewal is not appropriate," according to a statement released by the county.

Related: Investor dumps gunmaker

In the wake of the shooting, both Republicans and Democrats have called for tighter gun control, sending gunmakers' share prices into a tailspin on Wall Street. Shares of Smith & Wesson (SWHC) and Sturm, Ruger & Co (RGR). have tumbled over the last three trading days -- 19% and 15% respectively. Firearm retailer Cabela's (CAB) has also fallen 15%.

The uncertain outlook for the firearms industry may have sent a chill through investors, but the Florida store owner Smith said its led to an uptick in gun sales in the aftermath.

"When you have politicians saying we need to do something about assault rifles, people you wouldn't normally see buying a gun go out and buy one, because they're worried they won't be able to get one if they ban them," he said.