Modifies provisions relating to short-barreled rifles or shotguns

HB 1916 replaces Missouri's existing definitions for short-barreled rifles and shotguns with new, clearer language. The bill specifically defines a "concealable firearm" as any firearm with a barrel less than 16 inches in length, measured from the bolt or breech. This change directly affects owners of short-barreled firearms by establishing a concrete, measurable standard for classification under state law. The new definitions also clarify terms like "antique firearm" and "blackjack" to align with federal standards. This is a procedural update to the legal definitions, not a new restriction on firearm ownership.