Each airline has their own rules that they usually post on their website. Here is Delta's. I take everything I need in a metal gun case except the powder and primers but I was told I could bring the primers if I kept them in factory packaging. I just have my brother buy the powder and primers and have them waiting for me upon my arrival in Iowa.
Shooting Equipment
Shooting equipment is allowed as checked baggage only. It must fit within the very specific criteria that we outline below.
•Declare to the Delta representative that you are checking a firearm.
•Declare the existence of a firearm to security personnel if there's a security checkpoint before the Delta counter.
•All firearms must be declared by the passenger to a Delta representative at the main ticket counter.
•Present firearm(s) unloaded and sign a "Firearms Unloaded" declaration.
•Firearms must be packed in a locked manufacturer's hard-sided container specifically designed for the firearm, a locked hard–sided gun case or a locked hard-sided piece of luggage. Handguns may be packed in a locked hard-sided gun case, and then packed inside an unlocked soft-sided piece of luggage. However, a Conditional Acceptance Tag must be used in this case.
•Maintain entry permits in your possession for the country or countries of destination or transit.
•Ensure small arms ammunition is packed in the manufacturer's original package or securely packed in fiber, wood, plastic or metal boxes and provide separation for cartridges.
•You are responsible for knowledge of and compliance with all Federal, State or local laws regarding the possession and transportation of firearms. For more information about this regulation you can visit the TSA website.
•If you are transporting a firearm to the United Kingdom, a permit from the United Kingdom is specifically required. You must contact the United Kingdom for more information about securing this permit.
The following types of ammunition are not accepted:
•Gun powder; such as Pyrodex or Black Powder
•Ammunition with explosive or incendiary projectiles
•Ammunition, including case, exceeding 11 pounds (5 kg) gross weight per passenger
Pistols and accessories must be included in one case and contain:
•Pistol telescopes
•Noise suppressors
•A small pistol tool case
•No more than 11 lbs. (5 kg) of ammunition, including case