Oregon Revised Statutes Crimes and Punishments § 166.170

(1) Except as expressly authorized by state statute, the authority to regulate in any matter whatsoever the sale, acquisition, transfer, ownership, possession, storage, transportation or use of firearms or any element relating to firearms and components thereof, including ammunition, is vested solely in the Legislative Assembly.

(2) Except as expressly authorized by state statute, no county, city or other municipal corporation or district may enact civil or criminal ordinances, including but not limited to zoning ordinances, to regulate, restrict or prohibit the sale, acquisition, transfer, ownership, possession, storage, transportation or use of firearms or any element relating to firearms and components thereof, including ammunition. Ordinances that are contrary to this subsection are void.