It's Only 80%
It's all the craze, buy an 80% AR lower and build it into the ultimate tactical gun. It is perfectly legal for a person to build a firearm in their home as long as they are not prohibited from owning one. There are exceptions to that rule so be careful and look up the law. It is not legal for you to build a full auto or burst firearm period! So if you are doing it for that reason. DON'T! Now on to the meat of the subject. What is an 80% receiver? It is a forged or machined hunk of metal. Most of them the magazine well and the stock tube are machined. Most of them the magazine release area is also machined. However, That is all that is done. The fire control pocket is not milled out and the holes for the safety and the fire control pins are not drilled. First and foremost, don't "Dremel-Smith" the receiver. The area you need to mill out is very specific as far as what needs to be done. Measurements are crucial. Also, you need to know the difference between a Milling bit and a Drilling bit. Milling bits that you need will have a square faced cutting edge at the bottom of the bit, the sides of the bit will have a sharp cutting edge as well. With this configuration, you can drill and cut side to side. Perfect for hollowing out the Fire Control group area.
Drill bits are quite different, the cutting surface is only on the tip of the bit. It is not designed to cut on the side of the bit. The tip of the bit is also pointed instead of flat. Now you will need a good drill press, or a milling machine (preferred). A good solid vice for the drill press or Mill. Preferably one you can maneuver such as a mill vice available at Harbor Freight, Harbor freight Mill vice. The next thing you will need is a jig which you can purchase through the Brownell's link here. The Anderson Arms jig will work for most people that do not have a milling machine. The jig will help set the depth of the cut and where to cut. The jig's I use are ones made by American Weapons Components, formerly known as Aries Armor. These jigs are set up for people using a milling machine. but they work very well.
The next thing you need to do or should have already done is purchase an 80% lower receiver. There are hundreds of variants on the market. I haven't found one to be any different from the other. You will want to look for one that requires very little external finishing. Or you can take it to your local gunsmith that does Cerakote. Most 80% lowers have the mag well and the buffer tube area cut and threaded already. It is up to you to do the rest. Once you have these components and the proper bits you are ready to tackle making your own AR-15 or AR-10 platform rifle from scratch. Please pay attention to your local laws and make sure it is legal for you to own said rifle prior to purchasing parts. Now that you have the basic tools and set up to build a rifle, you are ready to begin. There will be 2 more segments on this process as it is long and does take some time. I look forward to seeing your pictures of your 80% build.
As alway, directly from the gunsmith's mouth.
U.S. Code 26 U.S.C. § 5842 "... anyone making a firearm shall identify each firearm, other than a destructive device, manufactured, imported, or made by a serial number which may not be readily removed, obliterated, or altered, the name of the manufacturer, importer, or maker, and such other identification as the Secretary [of the Treasury] may by regulations prescribe. (b) Firearms without serial number Any person who possesses a firearm, other than a destructive device, which does not bear the serial number and other information required by subsection (a) of this section shall identify the firearm with a serial number assigned by the Secretary and any other information the Secretary may by regulations prescribe. ===== 26 U.S.C. § 5871 — Penalties "Any person who violates or fails to comply with any provisions of this Chapter shall, upon conviction, be fined not more than $10,000, or be imprisoned not more than ten years, or both.
