LOS ANGELES, Calif. -

Bills to return a ban on assault weapons in the  United States will be introduced in both the Senate and House of  Representatives on the first day they are in session next month, California  Sen. Dianne Feinstein vowed on national television today

"We've tried to take my bill from '94 to 2004 and perfect it," the  California Democrat said on the NBC "Meet The Press" program.

Feinstein authored a federal ban on assault weapons in 1994, a ban that  was allowed to expire by Congress in 2004.

On NBC, California's senior senator said her staff has crafted a bill  that would "exempt over 900 specific weapons that will not ... fall under the  bill."

She said the 1994 assault rifle bill that she wrote was never challenged  in court by the National Rifle Association.

"Back in '93, when I told Joe Biden who was chairman of the Judiciary Committee that I was going to move this as an amendment on the Crime Bill, he  laughed at me," Feinstein said.

"He said, `you're new here. Wait till you learn'," Feinstein related.  "And we got it through the Senate, we got it through the House, the White  House came alive and ... the bill was passed." 

The NRA has declined to comment on gun issues since Friday's slaying of  20 grade school children and seven adults in Connecticut.

In 2002, the proposed extension of the assault weapons ban was opposed  by the Coalition Against the Semi-Auto Ban, a project of the National  Association for Gun Rights.

The group said the original legislation violated the right to keep and  bear arms guaranteed by the Second Amendment; claiming that what the law called  assault weapons were rarely used in crimes and that specifying a type of weapon  for a ban was a tactic that would lead to banning all weapons.

Feinstein, who just won her fifth Senate election, was propelled to the  forefront of California politics when she suddenly became mayor of San  Francisco when Mayor George Moscone and Supervisor Harvey Milk were  assassinated there in 1978. She has been a leading voice for gun control since  then.