Democrats in Colorado's House of Representatives have passed four new gun control laws.
Among them are limits to how many bullets a gun can hold and requirements for background checks on all guns sold, even between private parties.
Republicans opposed the measures saying they limit Second Amendment rights.
The Colorado bills are seen as test cases for national gun control laws being debated in Washington.
Vice President Biden lobbied Colorado lawmakers for their passage.
The state Senate still has to approve the package of bills.