"Firearm."  Any pistol or revolver with a barrel length less than 15 inches, any shotgun with a barrel length less than 18 inches or any rifle with a barrel length less than 16 inches, or any pistol, revolver, rifle or shotgun with an overall length of less than 26 inches. The barrel length of a firearm shall be determined by measuring from the muzzle of the barrel to the face of the closed action, bolt or cylinder, whichever is applicable.

§ 6106.1.  Carrying loaded weapons other than firearms.
(a)  General rule.--Except as provided in Title 34 (relating to game), no person shall carry a loaded pistol, revolver, shotgun or rifle, other than a firearm as defined in section 6102 (relating to definitions), in any vehicle. The provisions of this section shall not apply to persons excepted from the requirement of a license to carry firearms under section 6106(b)(1), (2), (5) or (6) (relating to firearms not to be carried without a license) nor shall the provisions of this section be construed to permit persons to carry firearms in a vehicle where such conduct is prohibited by section 6106.
(b)  Penalty.--A person who violates the provisions of this section commits a summary offense.

"Firearm."  An instrument used in the propulsion of shot, shell, bullet or any other object by the action of gunpowder exploded, explosive powder, the expansion of gas or the force of a mechanical device under tension.
(1)  "Automatic."  Any firearm which discharges more than once with a single pull of the trigger.
(2)  "Semiautomatic."  Any firearm which reloads without aid of the shooter, but fires only once with a single pull of the trigger.

§ 2503.  Loaded firearms in vehicles.
       (a)  General rule.--Except as otherwise provided in this
    title, it is unlawful for any person to have a firearm of any
    kind in or on or against any conveyance propelled by mechanical
    power or its attachments at any time whether or not the vehicle
    or its attachment is in motion unless the firearm is unloaded.
    The exceptions in this subsection do not apply when attempting
    to locate game or wildlife with an artificial light or when
    exercising any privileges granted by this title which may be
    exercised only when not in the possession of a firearm.