In firearms terminology, the firearm frame or receiver is the part of a firearm which integrates other components by providing housing for internal action components such as the hammer, bolt or breechblock, firing pin and extractor, and has threaded interfaces for externally attaching (“receiving”) components such as the barrel, stock, trigger mechanism and iron/optical sights. The receiver is often made of forged, machined, or stamped steel or aluminium; in addition to these traditional materials, modern science and engineering have introduced polymers and sintered metal powders to receiver construction. RECEIVER SETS

For the purposes of United States law, the receiver or frame is legally the firearm, and as such it is the controlled part. The definition of which assembly is the legal receiver varies from firearm to firearm, under US law. Generally, the law requires licensed manufacturers and importers to mark the designated receiver with a serial number, the manufacturer or importer, the model and caliber. In addition, makers of receivers are restricted by International Traffic in Arms Regulations.

Thus, in the case of a firearm that has multiple receiver parts (such as the AR-15, which has an upper and a lower receiver), the legally controlled part is the one that is serialized. For the AR-15 rifle, the lower receiver assembly is legally considered the actual receiver (although it is functionally a chassis that also houses the separate trigger group); while in the FN-FAL rifle, RECEIVER SETS, it is the upper assembly that is serialized and legally considered the receiver. This has led to prosecutors dropping charges against illegal manufacturing of AR-type firearms to avoid court precedents establishing that neither the upper nor the lower receiver individually contain all the components to be legally classified as a firearm.

Unfinished receivers

“Unfinished receivers”, also called “80 percent receivers” or “blanks”, are partially completed receivers with no serial numbers. Purchasers must perform their own finishing work in order to make the receiver usable. The finishing of receivers for sale or distribution by unlicensed persons is against US law. Because an unfinished 80% receiver is not a firearm, purchasers do not need to pass a background check. RECEIVER SETS, The resulting firearm is sometimes called a “ghost gun“.


Are 80% Lowers Legal?

Because 80% lower receivers are not considered firearms, they are federally legal to own. You don’t need to go through an FFL (Federal Firearms Licensed) dealer to buy one, nor do you need to conduct a background check or fill out a Firearm Transaction Record, Form 4473 to purchase one. Some states have placed restrictions on owning 80% lowers, while other states have banned their sale and ownership, which are detailed below.

Is it legal to buy an 80% lower receiver without an FFL?

Yes, it is completely legal under federal law to buy an 80% lower for personal use under the GCA of 1968. This means (in most states) you can buy and complete an 80% lower as long as you keep it for your own use, do not sell it or transfer ownership of once you have begun to mill out the fire control group.

A private individual producing a firearm for personal use and not for sale or distribution does not need an FFL transfer. This is a great plus for the average American with a family to protect because if the government decides they want to take away our firearms, your AR-15 build is ‘off the books’ since you completed it yourself. However, it is “recommended” by those agencies and government institutions who want to control your rights that you serialize and/or place special markings or identifiers on your finished firearm. Sure thing.