The bill, she said, will also ban big clips, drums and strips of more than 10 bullets.
Feinstein authored a federal ban on assault weapons in 1994, a ban that was allowed to expire by Congress in 2004.
"The National Rifle Association never brought the '94 assault weapons legislation to court - they knew it would be sustained from the beginning and I believe this will be sustained as well. You know, all of the things that society regulates - but we can't touch guns."
Feinstein said the purpose of the bill is to get weapons of war off the streets of our cities.