Mayor Diane Feinstein faces tough opposition locally and some state legal hurdles in her bid to enact a ban on handguns in San Francisco.
But a recently published study by two researchers at the University of California at Berkeley indicates that she and a group backing an initiative petition drive to freeze the number of pistols in California are on the right track.
In the Public Affairs Report of the university's Institute of Governmental Studies, Richard H. Seiden, a professor of behavioral sciences, and student Bruce R. Conklin say evidence clearly indicates that if guns were not so easily available the current ''alarming'' increase in suicides and homicides from gunfire would drop.
The United States gun-homicide rate is ''an incredible 50 times that of other industrialized nations,'' says Professor Seiden. He says there is an ''epidemic increase'' in homicides in the 15- to 24-year-old age group. The rate has doubled in the last 10 years - a problem unique to this country, according to Seiden. But he adds he doesn't think the US is more violent than other countries; rather, the high number of fatalities is linked to the easy access to guns here.
Mayor Feinstein is mindful that murders in San Francisco increased by 41 percent in 1981 over the number in 1980 and concerned about a general increase in violent crimes in the city. Thus she is having a handgun ban ordinance drafted for presentation to the city-county board of supervisors within the next three weeks.
But state Sen. H. L. Richardson, a member of the National Rifle Association and a leading opponent of gun control, obtained an opinion from the state legislative counsel that a city gun ban would be superseded by an existing state law. That law, pushed through in 1969 by Senator Richardson, says: ''It is the intention of the Legislature to occupy the whole field of regulation of the registration or licensing of commercially manufactured firearms.''
However, the city attorney has advised Mayor Feinstein that her ordinance would be legal, since the state law does not mention outright bans against owning handguns.
Californians Against Street Crime, the group backing the proposal to freeze the number of concealable guns in the state as of April 30, 1983, have until April 1 to collect 346,119 voter signatures to qualify their measure for next November's ballot.
A number of law enforcement officials, including San Francisco Police Chief Con Murphy and Foster City Police Chief John Norton, the president of the California Police Chiefs Association, are backing the petition drive of the group. Carefully drafted by attorneys of the Center for Law in the Public Interest in Los Angeles, the measure seeks to avoid the usual charges by antigun control spokesmen that all pistols would be confiscated and that eventually rifles and shotguns also would be banned.
The measure would require all pistols to be registered with the state attorney general by Nov. 2, 1983. Subsequently, only handguns already registered could be sold in the state - and only through licensed dealers.
Mayor Feinstein's ban would be patterned after one enacted in the Chicago suburb of Morton Grove, Ill. The San Francisco mayor and other advocates of such local laws say they despair of federal or even state -action because of the power of the gun lobby. ''We have to start somewhere,'' they argue.