The flood of calls and letters to the offices of the national handgun control lobby resulting from the shooting of former Beatle John Lennon and Washington physician Michael Halberstam is starting to recede.

Subsiding, too, are the predictable flurry of editorials calling for stricter federal gun laws and the round of television and radio "debates" on the issue.

Pete Shields, president of Handgun Control Inc., and Mike Beard of the National Coalition to Ban Handguns have been encouraged in the past by such temporary outpourings of support -- after the shootings of former representative Allard Lowenstein and San Francisco Mayor George Moscone, for instance.

But with the impending arrival of a new and more conservative Congress, and of a president who said at the time of the Lennon shooting that he doesn't favor tougher federal gun laws, they're not expecting passage of laws curbing gun ownership.

At the offices of the National Rifle Association, where gun control laws are "nonnegotiable," according to spokesman Jim Norell, the gun lobby with the real clout is preparing to renew its legislative attack on existing federal firearms statutes.

"Correcting the flaws" in law is the way Norell describes the NRA-backed bill, sponsored in the session just ended by 60 senators and 150 House members. "Gutting" the 1968 Gun Control Act is how opponents view it.

NRA officials are quick to acknowledge that their intent in the proposed bill is to make significant changes in the direction of enforcement policies of the Treasury Department's Bureau of Alcohol, Tobacco and Firearms which polices the 1968 law.

They accuse the agency of Gestapo-like tactics in harassing innocent gun dealers with statistic-building technical violations. The bill thus would put limits on unannounced inspections, a chief BATF tool.

The bill also would loosen current restrictions on the return of seized firearms and the availability of guns to persons indicted but not convicted of crimes. Opponents point out that, under the NRA-backed bill, an accused assassin, free on bond, could get a gun. The NRA blames that on some sloppy initial drafting.

Some revisions have been made in the bill, and it is sure to be pushed early in the new Congress, NRA officials said. Just as certainly, the NRA will rally its members to remind their representatives that they don't like any bill pushsed by groups that would control gun ownership.

"I'd rather see NRA spend $3 million [its lobbying budget] pushing for anticrime measures," said Norell, referring to issues such as mandatory sentences for those convicted of using guns while committing crimes. And in the next Congress, Norell predicted, the NRA "will spend a lot of money and a lot of effort" in these areas. "When you stop crime, the hue and cry for gun control will go away," he said.

Both sides agree with the statistics that say handgun abuses are predominantly an urban problem. It is estimated there are more than 50 million handguns in the nightstands and glove compartments of America.

FBI figures show that about 10,000 people in the United States are murdered each year with handguns. Last year in Japan, with half the U.S. population, 62 handgun murders were committed.

Shields said it is estimated that an additional 1,000 to 2,000 people die in handgun accidents each year and 10,000 more commit suicide with a handgun. He also cites figures showing that more than half the murders are committed by family members or friends, often in a moment of anger or passion.

The competing sides don't agree on the effect of restrictive state or local laws, and each can cite numbers to back its position.

For instance, when the U.S. Conference of Mayors issued a report last summer saying the strict District of Columbia handgun law had significantly reduced gun-related crime, it was immediately challenged by the NRA and the local police. They said better law enforcement tactics were the reason for the decrease.

A study trumpeting the effectiveness of a tough Massachusetts law that called for a one-year jail sentence for any one caught carrying a gun on the street was similarly criticized. Franklin Zimring, a University of Chicago law school professor who has studied the issue for years, said comparative statistics showed that gun crimes went down during the same period in other eastern seaboard cities that had no such laws.

"It's awfully hard to tie decreases in statistics to a specific countermeasure," he said.

Neal Knox, executive director of the NRA lobby, noted in a recent letter to the editor of The Washington Post that current gun laws didn't cover either the Lennon or the Halberstam killings. The accused murderer of the international rock musician bought his gun legally in Hawaii and transported it illegally to New York, which has strict local laws. The alleged Halberstam killer reportedly stole his gun from the home of an FBI agent.

A recent study in Florida showed that only about one-fourth of the guns used in crimes are bought from registered dealers. A like number are stolen, and about half are obtained in private transactions.

A 1979 gun control bill introduced by Sen. Edward M. Kennedy (D-Mass.) and Rep. Peter W. Rodino, Jr. (D-N.J.), chairmen of the Judiciary committees in Congress, proposed civil liabilities for handgun owners who don't tell authorities about the sale or trade of a gun that ends up being used in a crime.

That bill went nowhere. And a bill the Justice Department drafted for the Carter administration was never even introduced, because White House officials saw no sense in challenging the gun lobby in Congress, officials said.

Denis Hauptly, one of the bill's drafters, said, "A new handgun law needs active presidential support."

President-elect Ronald Reagan favors mandatory sentences, such as called for in a law enacted while he was governor of California, for gun crimes.

State law enforcement officials there, however, say the experience with the law was not encouraging, because prosecutors plea-bargained away the extra 5-to-15-year sentences, or judges refused to tack it on in sentencing.

So in 1976, the legislature passed a law taking such discretion away from judges and requiring a 1- or 2-year additional sentence. The law was challenged and declared unconsitutional State Attorney General George Deukmajian, one of the bill's authors, got a rare rehearing from the state supreme court, and the justices reversed their opinion.

But the new law has been in effect for only a year, and a spokesman for Deukmajian said it's too early to tell if it is reducing gun crimes. There is one perversely encouraging sign, he said: the number of stabbings is up.

For some longtime participants in the handgun control debate, the recent, if fleeting, surge of interest is too little or too late. Edward D. Jones III, a Justice Department economist who worked on its version of a firearms bill, for instance, said he's leaving the department after five years of struggling with the issue.

"I have a tremendous feeling of frustration," he said. "We haven't been able to do anything. We haven't been able to get a handle on the issue as public policy."

Ken Feinberg, who followed the issue as a Kennedy aide before entering private law practice, said he is a realist who knows tougher laws won't have the impact most advocates expect. "But even if it's true that new rigid gun control laws wouldn't have prevented the Lennon and Halberstam killings, they just might have prevented another death. What's the argument against trying?"

Charles F. C. Ruff, the U.S. attorney for the District of Columbia, is especially outspoken in his support of tougher federal handgun laws. He said the strict D.C. law against selling new handguns can be circumvented easily as long as neighboring states such as Virginia have weak laws.

"It just seems to me that if you know people are getting killed by handguns, you ought to see if it can be stopped. If not, okay, but no one's ever really tried it," he said.

To Ruff, the NRA's continual reference to the Second Amendment right to bear arms is nonsense.The amendment refers to the need for the militia to be armed, he noted, adding that stiff state and local gun control laws have never been found unconstitutional in that regard.

He said he was disturbed that the terms of the debate haven't changed at all: "People are dying and they [NRA supporters] are talking statistics."

Shields, of Handgun Control Inc., is equally frustrated after a recent round of talk-show discussions with the gun lobby. "I can't get on the same wave length with them at all," he said. "I'm talking about life versus violent death, and they're talking about murder rates like they were inflation or unemployment statistics."

Beard, of the gun ban coalition, said he is so pessimistic about the prospect of new federal controls that his group is concentrating on the state and local levels.

Shields, however, said he's going to try the same tactics that have been so successful for the NRA: pressure at the ballot box. His group has started a political action committee, and spent about $150,000 in the last election, mostly on the West Coast. He said Handgun Control's work led to the defeat of Rep. Bill Royer (R-Calif.), one of the biggest recipients of gun lobby money.

"We have to show political clout before we achieve legislative success," he said. "And unless the American people who support our position get on their high horse and demand some action from their representatives, we'll get some version of the McClure-Volkmer [the NRA-backed bill] passed in this next session."

Norell and John D. Aquilino Jr., articulate young spokesmen for the NRA, dismiss these complaints and stand behind their own well-documented arguments defending the place of the gun in American society.

They stress the association's programs of training, safety and competitive shooting for sportsmen. They also know that NRA's last big effort to stop the gun control forces obliterated efforts to write new regulations. Their organization generated more than 300,000 letters opposing the proposed BATF rules.

In the next Congress, they vow, the NRA will be heard from again.