A bill to repeal last year's restrictions on the size of ammunition magazines in Colorado is up for a vote.
A large number of people are expected to testify on the Republican proposal Monday before a House committee votes on it.
Democrats last year passed a law that prohibits the sale of ammunition magazines that hold more than 15 rounds. It became effective July 1.
Republicans are highly unlikely to succeed in repealing the law. The House committee hearing bill is controlled by Democrats with a comfortable 7-4 margin.
Another repeal attempt is being heard in the Senate Wednesday, where Democrats also have the votes to stop it.
The magazine limits are among a package of gun laws Democrats passed in the aftermath of mass shootings in Colorado and Connecticut.