Feinstein's bill would ban semi-automatic weapons — guns that fire one round and automatically reload — that can take a detachable magazine and have at least one military feature like a pistol grip.
It specifically bans 157 named weapons. In an effort to avoid antagonizing those who use them for sports, the measure allows 2,258 rifles and shotguns that are frequently used by hunters.
It also exempts any weapons that are lawfully owned whenever the bill is enacted.
Many expect the assault weapons ban won't be included in the basic bill the Senate debates next month, but will be offered as an amendment. That would mean it would likely need 60 votes to prevail in the 100-member chamber — a difficult margin for Feinstein since there are only 53 Democratic senators plus two independents who usually side with them.
"The vote is uphill. I truly understand it," she said.
Separating the ban from more popular measures would also make it easier for red-state Democrats to vote against the ban but still leave them available to back the rest of the legislation. Several senators said they thought the ban on high-capacity magazines could pass.
The House's Republican leaders have said they'll wait for the Senate to act before moving on legislation. They've not expressed support for an assault weapons ban.
They have discussed improving how states report data on people with serious mental health and drug abuse problems to the federal background check system. Both parties see that as a major flaw that needs to be fixed.
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