Handguns may not be shipped through the U.S. Postal Service by individuals without a FFL.
A variety of state and federal laws regulate the methods through which guns and their components can be shipped. These regulations are in place to make sure that guns only make it into the hands of Federal Firearms Licensees and other individuals who are legally allowed to own firearms. To ship gun components and parts properly and legally, it is important to be aware of the laws in both your state and the state where the person you are shipping the parts to is a resident. Laws are different depending on whether the person doing the shipping has a Federal Firearms License.
1. Determine if you are shipping parts or something legally considered to be a firearm. According to GunBroker, a website dealing with buying and selling guns, all guns contain at least one component that the ATF considers a firearm in and of itself. The parts that are firearms on their own will typically have their own serial number. These parts must be treated as firearms and shipped as if they were guns themselves. Parts that are not considered firearms do not face shipping restrictions that firearms do.
2. Determine if the person you are shipping the weapon or components to has a Federal Firearms License (FFL). If they do, you should be able to get their license number and verify it with the Department of Alcohol, Tobacco and Firearms if necessary. If the part or parts you are shipping can be considered a firearm, your recipient must have an FFL or you are committing a felony.
3. Arrange proper shipping for the items. Non-firearm parts can be shipped through any carrier service. If you have your own FFL, you can ship all manners of firearms through the U.S. Postal Service. Handguns must be shipped by a contract carrier (FedEx, UPS etc) if the sender does not have an FFL. Carrier service must be aware of what is in the package if it contains any part that is considered a firearm. It is advisable to ship gun components and firearms so that the recipient has to sign to receive them.