OH HB340

Establishes state law protections exempting firearms, firearm accessories, and ammunition manufactured and remaining in Ohio from federal interstate commerce regulation.

Defines covered items as those manufactured in Ohio from basic materials (such as unmachined steel and unshaped wood) without significant imported parts, excluding armor-piercing ammunition.

Excludes from protections certain weapons including those with bore diameter greater than 1.5 inches using smokeless powder, crew-served weapons, explosive ammunition, and multi-projectile firearms (except shotguns).

Requires firearms manufactured in Ohio on or after the effective date to be stamped with "Made in Ohio" on a central metallic part such as the receiver or frame.

Declares authority based on the Ninth and Tenth Amendments to the U.S. Constitution and Article I, Section 4 of the Ohio Constitution regarding rights to bear arms.