ID H0300

Establishes the "Idaho Small Arms Protection Act" as Section 18-3315C of Idaho Code, claiming state authority to protect gun rights beyond federal constitutional minimums based on the Second Amendment and Idaho Constitution Article I, Section 11.

Prohibits state officials and employees from assisting with federal enforcement actions on or after the effective date if such actions contradict Idaho Code or state constitutional provisions, and provides immunity from civil or criminal liability for non-compliance.

Defines "small arms" to include self-loading rifles, pistols, revolvers, shotguns, semiautomatic firearms with fixed or detachable magazines, and detachable magazines of any capacity, excluding only machine guns as defined by federal law on January 1, 2020.

Requires the Idaho Attorney General to challenge any federal actions—including federal laws, regulations, taxes, levies, fees, or stamps—that violate state constitutional protections for small arms in any Idaho court.

Allows the legislature by concurrent resolution to appoint bill sponsors or current members to intervene as a matter of right in any court case challenging this section's constitutionality, with authority to hire outside counsel at their discretion.