THE OFFICIAL RULES REGARDING GUNS ON PLANES
According to the TSA (Transportation Security Administration): "When traveling, comply with the laws concerning possession of firearms as they vary by local, state and international governments. If you are traveling internationally with a firearm in checked baggage, please check the U.S. Customs and Border Protection website for information and requirements prior to travel. Declare each firearm each time you present it for transport as checked baggage. Ask your airline about limitations or fees that may apply. Firearms must be unloaded and locked in a hard-sided container and transported as checked baggage only. Only the passenger should retain the key or combination to the lock. Firearm parts, including magazines, clips, bolts and firing pins, are prohibited in carry-on baggage, but may be transported in checked baggage. Replica firearms, including firearm replicas that are toys, may be transported in checked baggage only. Rifle scopes are permitted in carry-on and checked baggage. Declare the firearm and/or ammunition to the airline when checking your bag at the ticket counter. Contact the TSA Contact Center with questions you have regarding TSA firearm regulations and for clarification on what you may or may not transport in your carry-on or checked baggage.
"Unloaded firearms may be transported in a locked hard-sided container as checked baggage only. The container must completely secure the firearm from being accessed. Locked cases that can be easily opened are not permitted. Be aware that the container the firearm was in when purchased may not adequately secure the firearm when it is transported in checked baggage. Ammunition is prohibited in carry-on baggage, but may be transported in checked baggage. Small arms ammunition, including ammunition not exceeding .75 caliber and shotgun shells of any gauge, may be carried in the same hard-sided case as the firearm. Firearm magazines and ammunition clips, whether loaded or empty, must be securely boxed or included within a hard-sided case containing an unloaded firearm. Read the requirements governing the transport of ammunition in checked baggage as defined by 49 CFR 175.10 (a)(8)."