What is an AR 80% Lower Reciever?

AR 80% Lower

80% lowers such as 80% AR-15 Lower Receivers are items that have not yet reached a stage of manufacture to be considered a firearm. The term “80%” is actually just industry slang and not something endorsed/used by the ATF (Bureau of Alcohol, Tobacco, & Firearms).

We’ll cover some common FAQ’s, other examples of 80% lowers besides AR-15s, and recommended manufacturers. Disclaimer: I am not a lawyer and this is not legal advice.  Be sure to check all your local, state, and federal laws.

Are 80% lower receivers legal?

They are legal to own since they do not meet the definition of a firearm under the Gun Control Act of 1968 (GCA) and are often referred to as “paperweights.”  Just be sure that the manufacturer of your 80% has an ATF “determination letter” that specifically states their paperweight is not a firearm.

Do I need to be an FFL holder to make a firearm?

The short answer to whether you need a firearm license is “no” as long as you meet the following criteria:

  • Can legally own a firearm in your state/county/city (not a felon, etc…)
  • Manufacturing only for personal use
  • Configuration is legal in your state/county/city (National Firearms Act rules apply for short barreled rifles, automatics, etc…)

Do I need to add a serial number?

You as a private individual making a gun for yourself do not need to add a serial number.  However, it’s helpful to have one in case it gets lost or stolen.

Why are they silver in color?

Most 80% lowers are sold as raw aluminum but you can also find some anodized which is the standard coating.  However, when you complete an anodized 80%, all your cuts will expose the aluminum underneath.  Therefore we recommend going with a raw lower and finish it afterwards.

Once you complete your lower, you can have it anodized or coated in other popular coatings such as Duracoat, Alumahyde, or even just spray paint if you’re feeling fancy.

AR 80% Lower Receiver

How hard is it to finish an 80%?

You’ll need some specialized equipment such as a drill press or mill and some bits, but an 80% AR-15 lower receiver is very doable for someone who has patience and some mechanical inclination.  The AR-15 lower is quite forgiving since you are only machining out the pocket for the trigger and some pin holes.

What are common 80% examples?

AR-15 80% Lower

The most common 80% lower receiver project out there.  We recommend going with the leading manufacturer Thunder Tactical.  Their 80% has the rear lug already cut out which saves you a little time.

AR-10/.308 80% Lower

The big brother of the AR-15, the AR-10 is another 80% project that is becoming more popular.  It is very similar to the AR-15 in terms of difficulty.  Again, we recommend the 80% from Thunder Tactical.