9. As used in this section:
(a) “Ammunition” includes, without limitation, fixed cartridge
ammunition and the individual components thereof, shotgun
shells and the individual components thereof, projectiles for
muzzle-loading firearms and any propellant used in firearms or
ammunition.
(b) “Firearm” [means] includes, without limitation, a pistol,
revolver, rifle, shotgun, machine gun, submachine gun, black
powder weapon, muzzle-loading firearm or any device which is
designed to [be used as a weapon from which] , able to or able to be
readily converted to expel a projectile [may be expelled] through
the barrel by the [force] action of [any explosion or] an explosive,
other form of combustion [.
(b) “Firearm capable of being concealed” includes all firearms
having a barrel less than 12 inches in length.
(c) “Pistol” means a firearm capable of being concealed that is
intended to be aimed and fired with one hand.] or expanding gases.
The important part is "in this section" - it means that air guns, BB guns, most airsoft guns, paintball guns, etc., are all embraced within the meaning of "firearm" for preemption purposes, but the criminal codes which penalize carry, or regulate purchase/transfer, etc., are governed by the conventional definition of propelled-by-explosives.