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How do I finish an 80% lower?

You do not need to have any machining experience in order to finish our 80% lower receivers. All you need is a drill press, a few drills and end mills, and the 80% Arms Jig. You can view our step by step guide by clicking here.

Do you have an ATF determination letter?

Yes, we have received a letter from the ATF certifying that they do not consider our 80% lower a firearm. You can download a copy of this letter here.

Is this legal?

Yes, in our home state of California, as well as almost every other state in the U.S., it is legal to build your own firearm for personal use, as long as you can legally own a firearm. You must build the lower yourself; it is not legal for somebody else to do it for you. You are not required to engrave a serial number or any other information on the lower, unless you later decide to sell it.

From the ATF:Individuals manufacturing sporting-type firearms for their own use need not hold Federal Firearms Licenses (FFLs). However, we suggest that the manufacturer at least identify the firearm with a serial number as a safeguard in the event that the firearm is lost or stolen. Also, the firearm should be identified as required in 27 CFR 478.92 if it is sold or otherwise lawfully transferred in the future. 


If I live in California, are completed 80% lowers subject to the CA Assault Weapons ban?
Do I need a bullet button?

Completed 80% lowers are subject to all the same laws that apply to any normal firearm. If you live in CA, you need to be careful to follow the laws related to the assault weapons ban. In general, if you build AR-15 style rifle with a pistol grip, you will need a "bullet button". There are also "featureless" configurations that do not require a bullet button. For more info on following CA laws, has a very helpful flowcart:

Disclaimer: We are not lawyers and cannot provide legal advice. Check your local laws and make sure to follow all of them.