Whether you are just getting into the idea of an 80% lower receiver, or if you are an experienced operator who has made multiple AR-15s, it is always important to note, for the newbies, what it is and what is could be beneficial or otherwise.
First of all, what is an 80% or unfinished lower receiver? Well, simply, it is a lower receiver that is, obviously, not finished. It has not yet received a serial number, but the metal has not attained the attributes that would make the ATF and GCA qualify the lower receiver as a gun as of yet.
The piece of metal is only at 80% completion and therefore, does not require any type of permit paperwork, transfer, FFL or serial number.
So now that you know what it is, why would anyone want to buy something for their weapon that is not considered manufactured and complete?
Quite a few operators like the endeavor of building their own AR-15. The process of buy the parts, milling the lower receiver, and having the option to customize their weapon as they see fit.
But the first thing to mention and realize, that if this is the quest you are on: to build your own AR-15, you have to realize that it is very time consuming, very expensive, but potentially very much worth it in the end.
Back to the question at hand, why buy 80 lowers that are not considered complete? Well, a lot of operators want the option to brand their own weapon, use their own lingo to identify the Safe/Fire switch, or simply, they want the option to make their lower receiver look as badass as possible. A truly unique weapon, that they can brag to their buddies about having built by hand, and have their branded logo on it as the proof in the pudding.
Buying an unfinished lower receiver and building your own AR-15 is a labor of love. After you build your first one, and put your own design or logo on your lower receiver, you will come to notice that you don’t really fancy a receiver that is mass produced.
Whether you don’t like the excessive markings, the hassle of buying the finished lower receiver without it even being able to fire, or just the fact that you would rather be able to say that you made your weapon by hand.
Once you have built your own, it is tough to just buy an AR-15 off the shelf without wanting to make changes or customizations. Especially if this is not your first time building a weapon.
It is important to realize that you MUST realize that specific states have more restrictive and specific laws than what is regulated by the ATF and GCA.
So before making the leap and decision to start building your own arsenal of AR-15s, make sure doing so is legal in your state.
This is something that can be asked of you local township municipality or you can even contact the ATF directly and ask them as well. Even a simple Google search should give you the answer.