The National Rifle Association has had its barrel bent.

For years it fought to wipe out the Treasury Department's Bureau of Alcohol, Tobacco and Firearms, employer of the dreaded gun police.

Finally, under a sympathetic conservative president who had received the NRA's support, the organization got its wish; the Reagan administration announced formally last year it would abolish the agency.

But now the NRA wants to breathe life back into BATF.

The problem: the president decided to transfer enforcement responsibility for firearms laws to the Secret Service, and gun owners fear that agency will be more zealous than the bureau ever dared to be.

"The NRA suddenly realized they weren't going to have BATF to kick around anymore. The Secret Service is more respected and well known, and not as vulnerable to attack by the NRA. They realized they had outsmarted themselves," said one Senate source.

The flip-flop has produced some amazing politics.

The NRA has spread the word that it would prefer to see the bureau left intact for enforcing the firearms laws, but with its budget and personnel cut. One observer said the NRA is trying to "turn BATF into the Karen Ann Quinlan of law enforcement."

In testimony last week before the Senate Appropriations subcommittee that oversees the agency's funding, Neal Knox, president of the NRA, publicly opposed the transfer, saying gun owners are concerned now that if it occurs, "there will be more enforcement, not less."

That subcommittee is chaired by Sen. James Abdnor (R-S.D.), who was elected in 1980 with the help of almost $25,000 in NRA contributions and private expenditures. In a hearing last month, Abdnor said, "I don't take a back seat to anyone in support of the NRA. I'm opposed to gun control. I wonder if we might not be going from the frying pan into the fire" in transferring the job to the Secret Service.

On Wednesday night, Abdnor and Sen. Dennis DeConcini (D-Ariz.) met with Treasury Secretary Donald T. Regan to present a bipartisan congressional alternative to the administration's plan.

Under the Abdnor-DeConcini plan, according to a memo they wrote, the Secret Service would have authority for arson and explosives and would take over about a third of the bureau's agents. BATF would become the "Treasury Compliance Agency" with responsibility for fireams law enforcement and for alcohol and tobacco regulation.

The plan also calls for the Treasury secretary to conduct a major management study of the bureau and to "crack down on the identified causes of past and present abuses by agents . . . in the firearms area."

The note at the bottom of the proposal: "The proposed alternative has the support of the National Rifle Association."

Ronald Reagan, a lifetime member of the NRA, is faced now with the awkward question of what to do.

Marlin Fitzwater, a spokesman for Treasury, confirmed yesterday that the meeting had taken place. He said the issue is being considered, but "no decision has been reached. There are no changes at this point."

Sources familiar with the issue said there is dissension in the department over the new proposal, with heavy resistance coming from law enforcement officials.

Michael Freeman, a spokesman for Abdnor, said yesterday that if Regan refuses to go along with the proposal, there may be no reorganization at all. "They have the option of taking the congressional plan or having no reorganization at all. The reorganization proposed by the Treasury Department is unacceptable to the subcommittee."

Robert Mills, a staff member for the committee, said, "That plan is in big trouble . . . frankly because Treasury officials in charge of explaining the reorganization plan have done a lousy job."