WASHINGTON (AP) _ Gun lobbyists challenged congressional efforts Wednesday to ban weapons that cannot be detected by magnetic screening devices, telling the lawmakers that such legislation would be unfair and futile.

''We believe that the clear and compelling priority is for better security personnel with state-of-the-art detection equipment,'' James Jay Baker, government affairs director of the National Rifle Association, told members of the House crime subcommittee.

The panel has been considering several bills that would block the availability of weapons, such as plastic or ceramic guns, that cannot be detected by devices such as airport screening equipment.

Such firearms are not yet on the market, but lawmakers have said that the technology to produce them is already available.

Representatives of firearms groups told members of the panel that non-metal guns will eventually become available.

''They are lighter, less subject to cold and wet, not subject to corrosion, not as demanding of lubrication, and often are less expensive to manufacture, resulting in improved performance at lower cost,'' said Neal Knox, director of The Firearms Coalition.

Legislation restricting these guns ''would unfairly burden the firearms manufacturer and consumer by potentially denying, or at least inhibiting, the use of advanced ... (materials) in firearms,'' Knox said.

Lawrence D. Pratt, executive director of Gun Owners of America, added, ''Since the development and use of plastic guns is not the exclusive domain of the United States, it would be futile to attempt to suppress this technology by legislation.''

After several firearms lobbyists told the panel that the real need is for improved airport security, Rep. William Hughes, D-N.J., chairman of the subcommittee and a supporter of the legislation, responded.

''Is it your testimony we should in fact wait until a crisis to deal with the problem ... ,'' he said to one of the witnesses. ''What are you suggesting we do? Wait until there are 500,000 plastic or ceramic weapons on the market before we deal with it?''

Later, John M. Snyder, spokesman for the Citizens Committee for the Right to Keep and Bear Arms, argued that improved detection devices would be a better deterrent than laws banning the weapons, offering the lawmakers a new twist on the familiar gun-lobby slogan, ''Guns don't kill, people do.''

''The cause of terrorism is terrorists, not plastics,'' he said..