The Gas-Operated Semiautomatic Firearms Exclusion Act aims to regulate the importation, sale, manufacture, transfer, receipt, and possession of gas-operated semiautomatic firearms, along with large-capacity ammunition feeding devices and rapid fire devices. The act sets enforcement timelines, with prohibitions starting on July 1, 2025, and possession restrictions beginning on January 1, 2026. Exceptions are made for certain government entities and for firearms manufactured before these dates, provided they are certified by the owner. The Attorney General is responsible for creating a list of prohibited firearms and developing a certification system for existing firearms. The act also defines key terms and mandates that licensed dealers mark regulated firearms according to the Attorney General's guidelines, while establishing penalties for violations, categorizing offenses related to machine guns and rapid fire devices as fourth-degree felonies.

Additionally, the bill introduces new provisions for the certification of firearms, requiring licensed dealers to make certification forms available for law enforcement inspection and to submit these forms to the Attorney General if they cease operations. The certification must confirm legal possession and include specific details about the firearm and the individual, while also stating that the information is confidential. New regulations for nonresidents transporting firearms are established, allowing them to transport unloaded and secured firearms within a specified timeframe, with a certification required for those moving into the state. Violations of the act are classified as misdemeanors, while committing a felony offense while in possession of a regulated firearm is classified as a fourth-degree felony. A severability clause is included to ensure the act remains enforceable even if parts are deemed invalid.