Is it difficult to machine an 80% lower? thumbnail image

Is it difficult to machine an 80% lower?

80 Percent Arms   |   Jun 4th 2020

It can certainly be daunting to machine your first 80% lower receiver or frame. You might be worried about the mess, hurting yourself with power tools, or whether the holes you drill out will be perfectly straight — but don’t worry, it’s so much easier than it seems! We’ll go over all your potential concerns and provide you tips from our first hand experience and knowledge of having milled out several 80% lowers ourselves.

What is involved in machining an 80% firearm?

We understand that not everyone has experience with power tools so just to reiterate, don’t be scared! Once you get the hang of it you’ll end up wanting to do even more machining yourself (it’s kind of a bug).

Although the process to complete the last 20% to complete that receiver blank requires some machining it can actually be done with fairly common tools that don’t cost a lot on their own. In fact, some of these tools just might be collecting dust in your garage right now.

How much does it cost to mill out an 80 lower?

So assuming you’re starting out with absolutely nothing, you should expect to be paying around $500 to $600 dollars for all the required tools, equipment and supplies needed to have a proper setup to machine your 80-lower and any future 80% lowers into a 100% firearm.

What is required to finish an 80% lower receiver?

The tools, equipment and supplies required include the following:

To save some money on tools you could try to look for second-hand tools being sold online on apps like Offer-Up or Facebook Marketplace. However, for specific tooling such as the 80 lower jig and the respective drill bits or end mill we recommend those to be new for the best results. For well equipped builders, you may want to use a drill press for the absolute best possible accuracy when drilling the safety selector and trigger group pin holes into the receiver.

If you’re working on an 80% pistol frame the only additional tools you’d need to add to complete your gun builder ensemble would be a dremel kit and a quality punch set made specifically for firearms. But of course, if you already have some of these tools then you’ll be pleased in being able to save even more money and get a new opportunity to use them as well.

Who can mill my 80% lower?milled out 80% lower

If you haven’t figured it out by now, the answer is everyone and anyone (technically). Anyone with the proper tools is capable of milling out an 80% lower. Legally speaking, it’s a slightly different story. If someone else finishes your 80 lower receiver for you as a service then they would be considered illegally manufacturing firearms for the purpose of sale or distribution.

For profit ventures are quite self explanatory but an example of ‘distribution’ is if a friend milled out your lower for you for free and gave it back to you — still illegal. The ATF is quite clear on this as this is defined in the Gun Control Act of 1968.

The same goes for tools. Tools for building out your 80 lower cannot be loaned out to you or anyone else. If you want to stay above board and compliant you’ll have to get the lower serialized in order for gunsmiths to do any work on it or assemble it for you. However, gunsmiths can serialize your lower for you at any point in the process; before or after the 80 percent lower receiver is completed.

Are 80 Lowers Illegal now?

No, under the Gun Control Act of 1968 and the ATF’s definition of what is classified as a firearm, 80 lowers are still legal to be sold, possessed and built out in most states. Some states have banned the sale and possession of “ghost guns” which means we can’t ship 80% lower receivers to the following states: Connecticut, Hawaii, New Jersey, New York, Rhode Island, and Washington D.C..

Every state has different policies and regulations when it comes to 80 percents. It is up to you to be aware, familiar with and to follow your state and local ordinances.

However, that could all change if the ATF’s new proposed rule to redefine a “frame” or “receiver (2021R-05) passes. So please, if you haven’t already, go comment against this unconstitutional and un-American policy on the ATF’s website. The comment period ends on August 19, 2021!

What’s an 80% lower?

Quite simply, an 80% lower is an incomplete lower receiver which requires additional tooling and machine work before it can be used as an actual firearm. Therefore, the ATF currently does not recognize 80% lowers as firearms. What does this mean for you? It means you don’t have to order your 80 lower through an FFL. This cuts out the middleman so to speak and saves you a trip to your local store along with money from fees you don’t have to pay. Ship the beginning of your new AR build straight to your house and start cutting away that last 20% of metal needed to insert a trigger group and safety selector. Once you’ve done that, you have a 100% completed firearm on your hands.

Get Started On Your First 80 Lower Build!

If you are more of a visual learned and need help in seeing the process for how to build your 80 percent lower, check out our blog on that and you’ll see how simple the steps are! You can also reference our Easy Jig Gen 3’s user manual