The Transportation Security Administration (TSA) has strict guidelines for passengers wishing to transport firearms on an aircraft. All firearms must be declared to the airline. The TSA definition of firearms includes any weapon which will, is designed to or may be easily converted to expel a projectile by the force of an explosive. TSA also classifies as a weapon the frame or receiver of any such weapon, any firearm silencer or muffler or any destructive device.
A Pennsylvania man was recently arrested at BWI-Thurgood Marshall Airport after a loaded gun was detected in the man's carry-on bag. Police confiscated a .380 caliber firearm that was loaded with five rounds. He also had in his bag an additional magazine loaded with six rounds. The man was reportedly heading to Las Vegas. He was arrested and now faces state weapons charges.
Firearms, firearm parts and ammunition are not permitted on carry-on bags. Passengers also may not have realistic replicas of firearms in carry-on bags. Black powder is also prohibited as well as percussion caps used with black powder. Rifle scopes are permitted, however.
Someone wishing to transport a firearm must transport it in a checked bag. The firearm must be unloaded and in a locked container with hard sides. Firearms must be packed separately from ammunition. Weapons charges at the airport can be easily avoided, however, by following the TSA rules for firearms in checked bags. In addition to criminal charges, someone who brings a weapon to the airport check-in may be subject to civil penalties from TSA.
Source: abc 2 News, "Pa. man arrested after discovery of a loaded gun at BWI," August 12, 2013