A law requiring fixed magazines that hold no more than 15 rounds for certain types of semiautomatic firearms is set to come into effect in Colorado on Aug. 1.
The law also requires classroom training, background checks, and approval from law enforcement for an individual to receive a permit to purchase one of the affected firearms.
The legislation, which was signed into law by Gov. Jared Polis on April 10, 2025, was challenged in court the following September.
Second Amendment advocates say the law is a de facto “assault weapons” ban.
Rather than banning specific guns, Colorado SB25-003 lists the characteristics of firearms that must have a fixed magazine that holds no more than 15 rounds. …