The state of Pennsylvania has a specific definition of what they consider a firearm. A weapon is considered a firearm if it is:
- A pistol or revolver with a barrel length of fewer than 15 inches.
- A shotgun with a barrel length of fewer than 18 inches.
- Any rifle with a barrel length of fewer than 16 inches.
- Any pistol, revolver, rifle, or shotgun with an overall length of fewer than 26 inches.
You can measure the length of a firearm’s barrel by measuring from the barrel’s muzzle to the face of the closed action, bolt, or cylinder.
Weapons like grenades and rocket launchers are not specifically classified as firearms but as destructive devices. Destructive devices were classified as firearms by the National Firearms Act, so on the federal level, they would be considered firearms. Federal supersedes state, so they must be treated as firearms by every state.