By MALCOLM GAY

NASHVILLE - Happy-hour beers were going for $5 at Past Perfect, a cavernous bar just off this city’s strip of honky-tonks and tourist shops, when Adam Ringenberg walked in with a loaded 9-millimeter pistol in the front pocket of his gray slacks.

Mr. Ringenberg, a technology consultant, is one of the state’s nearly 300,000 handgun permit holders who have recently seen their rights greatly expanded by a new law ? one of America’s first ? that allows them to carry loaded firearms into bars and restaurants that serve alcohol.

“If someone’s sticking a gun in my face, I’m not relying on their charity to keep me alive,” said Mr. Ringenberg, 30 . Gun rights advocates like Mr. Ringenberg may applaud the new law, but many customers, waiters and restaurateurs here are dismayed by the decision.

“That’s not cool in my book,” Art Andersen, 44, said at Sam’s Sports Bar and Grill near Vanderbilt University. “It opens the door to trouble. ” Tennessee is one of four states, along with Arizona, Georgia and Virginia, that recently enacted laws explicitly allowing loaded guns in bars. The new measures in Tennessee and the three other states come after two landmark Supreme Court rulings that citizens have an individual right to keep a loaded handgun for home defense.

The rulings, which overturned handgun bans in Washington, D.C., and Chicago, have strengthened the stance of gun rights advocates nationwide. More than 250 lawsuits now challenge various gun laws across the country.

State Representative Curry Todd, a Republican who introduced the gunsin- bars bill here, said that carrying a gun inside a tavern was never the law’s primary intention. Rather, he said, the law lets people defend themselves while walking to and from restaurants. “Folks were being robbed, assaulted ? it was becoming an issue of personal safety,” said Mr. Todd . Under Tennessee’s new law, gun permit holders are not supposed to drink alcohol while carrying their weapons. But critics of the law say the provision is no guarantee of safety .

“Guns and alcohol don’t mix; that’s the bottom line,” said Michael Drescher, a spokesman for Governor Phil Bredesen of Tennessee, a Democrat, who vetoed the bill but was overridden by the legislature. The law allows restaurant and bar owners to prohibit people from carrying weapons inside their establishments by posting signs .

But many restaurateurs are reluctant to discourage the patronage of gun owners. So far, the law has been challenged only once. Filed by an anonymous waiter, the complaint contended that allowing guns into a tavern creates an unsafe work environment . His complaint was denied by the state’s Division of Occupational Safety and Health.

“A loaded concealed weapon in a bar is a recognized hazard,” said David Randolph Smith, a lawyer who represents the waiter and is preparing to appeal the decision. “I have a right to go into a restaurant or bar and not have people armed. And of course, the waiter has a right to a safe workplace.” Down at Bobby’s Idle Hour, however, Mike Gideon said he did not believe that guns in bars were unsafe.

“People who have gun permits have the cleanest records around,” said Mr. Gideon, 54. “The guy that’s going to do the bad thing? He’s not worried about the law at all.”