Boomyal, folks like us like the idea of buying 80% lower receivers for a few reasons. First it is the fun to building your own gun. Secondly, when you build your own gun, it doesn't have to be registered with anybody and it is totally 100% legal as well. What an 80% lower actually is, is a AR15 lower receiver that doesn't have the trigger area milled out of the aluminum section yet. So therefore it is sold as a piece of metal and there is no restriction for anybody to buy them. You don't fill out any paperwork of have to prove you are 21 YO or anything like that. It is like buying anything else on the net. You simply buy and they send. Absolutely legal. There isn't any backroom shenanigans going on or any under the table junk either. The ATF knows all about this and states it is legal. AND, if you don't want to, you don't have to put any serial number or markings on the gun either. It can be plain without any such things marked on it. Some put their own identification markings on it so if it gets stolen, you can identify it. The only restrictions are, you can't sell it to anybody or even give it away. That is considered manufacturing then.
So buy a few and have at it. The critical threaded areas are already machined and the magazine well is finished as well. You only have to mill out the trigger group areas. So if you own a drill, you can build one. They sell the templates so you can do that as well. Check You Tube for some videos and watch them. JMHO!
Oh one last thing. The 80% lowers are not only restricted to AR15's, you can also make AR10's and 1911 45ACP guns as well. Lots to do in this world if you like those types of things. :thumb: