SAN FRANCISCO — The only gun store in San Francisco is shuttering for good, saying it can no longer operate in the city's political climate of increased gun control regulations and vocal opposition to its business.

"It's with tremendous sadness and regret that I have to announce we are closing our shop," High Bridge Arms manager Steve Alcairo announced in a Facebook post on Sept. 11. "It has been a long and difficult ride, but a great pleasure to be your last San Francisco gun shop."

Alcairo said the breaking point came this summer when a local politician proposed a law that would require High Bridge Arms to video record every gun sale and submit a weekly report of ammunition sales to the police. If passed, the law would join several local gun control ordinances on the books in a city still scarred by the 1993 murder of eight in a downtown high-rise and the 1978 assassination of Mayor George Moscone and gay rights activist Harvey Milk.

Dear friends and family, it's with tremendous sadness and regret that I have to announce we are closing our shop. For... Posted by Highbridge Arms on Friday, September 11, 2015

"I'm not doing that to our customers. Enough is enough," Alcairo said. "Buying a gun is a constitutionally protected right. Our customers shouldn't be treated like they're doing something wrong."

The announcement prompted an outpouring of sympathy and anger online from gun enthusiasts — and a steady stream of customers eager to take advantage of going-out-of-business prices.

A second Facebook page with the store's name was flooded with comments in support of the shop, urging Alcairo to appeal to the National Rifle Association for help or relocate to Texas, where gun stores are plentiful and regulations light. One commenter likened San Francisco lawmakers to "Nazis."

"Now what are the San Francisco ass clowns going to say when violence doesn't stop," another wrote. "Typical liberal morons just wait I'm going to laugh when crime goes up."

The new rifles lining the store's walls are quickly dwindling, and the handguns in the glass cases are going fast. So are T-shirts that boast in English and Chinese that High Bridge is "The Last San Francisco Gun Store."

For years, the High Bridge Arms weathered mounting restrictions imposed by local lawmakers and voters, who passed a handgun ban in 2005 that a judge later struck down. The gun store increasingly stood out in the gentrifying Bernal Heights neighborhood of hot restaurants, trendy bars and a chic marijuana dispensary, while weathering organized campaigns calling for its closure.

High Bridge will close Oct. 31, Alcairo said.

Supervisor Mark Farrell said he introduced the latest bill to help police combat violent crime in the city. "Anything that makes San Francisco safer, I support," he said.

Farrell said the bill hasn't been voted on, and he doesn't understand why the store is closing now. He said it was "comical" that the High Bridge is blaming its closure on a proposed law still months away from taking effect.

Alcairo said news coverage of the bill's introduction in July slowed sales considerably because customers wrongly believed their purchases would be recorded and turned over to police. He said he had to lay off three clerks and that sales slumped throughout the summer. The store's summer slump comes amid an overall gun sales surge in the state, according to California Department of Justice statistics.

The California DOJ reported 931,000 guns sold last year— three times the number sold in 2004 and the second highest annual number since the department began keeping sales records in 1991.

In the end, Alcairo said, he and the High Bridge Arms owner tired of the continued opposition and mountains of paperwork required by the San Francisco Police Department, state Department of Justice and the U.S. Bureau of Alcohol, Tobacco, Firearms and Explosives.

Alcairo grew up near the store and says he is angry and disappointed with San Francisco.

"This is the city that defended gay marriage and fights for unpopular causes like medical marijuana," he said. "Where's my support?"

Champion pistol shooter Bob Chow opened the store in 1952, four years after competing for the United States in the summer Olympics in London. Chow sold the store to Andy Takahashi in 1988. Chow died in 2003. Takahashi, who also owns the building that houses the store, declined to comment.

Alcairo said the owner shouldn't have a problem attracting another type of business in economically booming San Francisco.

The quirky city fixture attracted gun enthusiasts from around the world, many posing in photos with Alcairo and his pistol-packing clerks. Alcairo said professional athletes would visit the store when playing in San Francisco for the novelty of buying a weapon — and a T-shirt — from the city's last gun store.

"High Bridge has always taken care of me," said Chris Cheng, a San Francisco resident who calls it "my home store." Cheng won a $100,000 cash prize and a professional marksman contract after winning the History Channel's "Top Shot" competition.

"It's always been a challenge for the store to do business in San Francisco," Cheng said.

Additional reporting by Mashable.