Best AR-15 80% Lowers – 2020 Buyer’s Guide

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Eighty percent lowers are the latest trend among AR-15 enthusiasts. This unfinished receiver is low in price and helps the user avoid some legal formalities while enjoying the fact that he’s machining the receiver himself.

Here, we’ll be talking about what an 80% lower receiver is, how much work and effort are required to customize it, and the legal requirements associated with it. We will also discuss some important factors to consider before buying.

To help you out with this task, this article also outlines some of the best options currently available on the market.

Comparison of the Best 80% Lower Receivers

PRODUCTDETAILS
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Brownells AR-15 80% Lower Receiver

  • Best Overall 80% Lower Receiver
  • Made from 7075 T-6 Aluminum
  • Available in black or unfinished
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​Matrix Arms AR-15 80% Lower Receiver Forged

  • Available in black or unfinished.
  • Constructed with high-quality aluminum
  • Can be able to work with most upper receivers
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James Madison Tactical AR-15 80% Polymer Gen 2

  • Available in a black finish
  • Designed to fit .223 rifles
  • Made from durable polymer
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Polymer80 AR-15 80% Polymer Lower Receiver and Jig Kit

  • Available in various finishes
  • Made from high-quality polymer
  • Available for 5.56 NATO or .223 caliber rifles.
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Anderson Manufacturing AR-15 80% Lower Receiver

  • Unfinished design
  • Made from 7075 T6-Aluminum
  • Designed for .223 AR-15 rifles.
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What is an 80% Lower Receiver?

An 80% lower receiver is nothing but a simple milled or forged piece of metal which looks like an AR-15 lower receiver but without the fire control group cavity. In simpler terms, it is an unfinished AR-15 lower receiver which requires the user to do some milling and drilling in order to make it functional.

The part where the trigger assembly is installed is solid and the user must drill and machine this part to convert it into a stripped lower receiver.

Legally, a lower receiver is considered to be a firearm itself and hence, is required to bear a serial number. That is because a lower receiver houses the fire control group and connects all the basic functioning parts of a rifle.

Due to its unfinished design, this type of device is not considered a firearm by the ATF. This means that it does not require a serial number for sale and purchase. A rifle made with such a receiver can be owned and used in the state, county, or city you reside in without any serial number, at least under federal law.

ar-15 rifle

On the other hand, the ATF does recommend users of such self-made AR-15 rifles engrave some serial number and info on such receivers. This helps in case such firearms are lost or stolen. (We’ll try to stay apolitical for the purposes of our article here).

It is important to note here that an 80% lower receiver is not considered a firearm if used only for personal use. If you finish this receiver for a weapon to be sold or lawfully transferred in the future, it must bear a serial number in accordance with 27 CFR 478.92 regulations. You should also always check with your local firearm laws and regulations beforehand.

Legal Requirements for Registration

Legally, an 80% lower receiver does not have to be registered or have a serial number. They can be sold to anyone with or without an FFL. A person who buys one can machine and drill it to make a complete lower receiver and hence, make a complete AR-15 rifle.

Such weapons are not required to have a serial number under federal law. Be sure to be aware of your own state’s laws (looking at you, Californians!).

However, the user can neither transfer nor sell this firearm. If the user intends to sell or transfer such an AR-15 he/she has to get their weapon registered and serialized.

The laws about sale and transfer are somewhat confusing. That’s because you can gift such a weapon to someone if you manufactured it for your own use. On the contrary, if you manufactured such a weapon with the intent of gifting it, you must be sure it's serialized.  

The catch here is how somebody (from the law) is going to prove your intention. Confusing, isn’t it?

None of this is legal advice. We’re only presenting our own understanding of the law. Local laws can vary, as well.

Factors to Look For When Buying

There are several factors you must consider seriously before choosing an 80% lower receiver for customization. These include:

Material

The first and foremost factor to consider when choosing an 80% lower is the material. Lower receivers are generally made either of aluminum or polymer.

Aluminum can be further divided into 6061-T6 and 7075-T6 variants, where the former is more of a general-purpose material and the latter is high-quality and more durable.

Aluminum lowers, being pure metal, are a bit difficult to mill and drill. Polymers on the other hand are softer and require less effort for customization.

On the contrary, aluminum is long-lasting and more durable than polymer. We recommend using aluminum lowers but it is still a matter of personal discretion.

Finish

Eighty percent lowers are generally type II or type III hard-coat anodized which makes them abrasion and corrosion-resistant. Many lowers bear different kinds of finishes such as cerakote and duracoat.

Buying an anodized 80% lower might not be an intelligent choice. That’s because you’ll be milling and drilling the receiver to customize it, which is eventually going to expose the inner layers of the metal which are not anodized.

This means you’ll have to get the lower receiver anodized after finishing it. So it’s better to stay with the non-anodized or simple aluminum 80% lowers.

On the other hand, polymer receivers don’t face such an issue because you are only exposing layers of the same material while machining.

Brand

Always aim to buy an 80% lower receiver from a well-known manufacturer or a trusted firearms dealer.

Eighty percent lowers are required to be drilled and machined for completion, so they must have tight tolerances and precise working points.

Low-grade manufacturers can deliver hit-or-miss products, which can eventually lead you into trouble while finishing.

Aesthetics

You want your weapon to look good, right? Aesthetics are also an important aspect while choosing an unfinished lower for customization.

Consider the color, design, and any engravings on the 80% lower to match your aesthetic needs.

Quick Take - The Best AR-15 80% Lowers

Review of the Best AR-15 80% Lower Receivers

Let’s look at a few of the top models that meet our criteria for a quality piece you can build your own rifle around.

Pros

  • Aesthetically sharp
  • Super-durable construction
  • It can fit most lower receiver parts
  • Easily fits most AR-15 uppers receivers
  • Easy to install, usually takes a few minutes

Cons

  • None

What Recent Buyers Report 

This 80% lower receiver received a lot of praise from most users. They managed to install this easily without issue within a few minutes. Most of them were either using this for an upgrade or as an add-on to a building project. One user said it even accepts most lower receiver parts.

Why it Stands Out to Us

This is made from a tough type of aluminum known at 7075 T-6 aluminum. It can take a lot of hits and does have the potential to last longer than any lower receiver on the market. On top of that, it works well with most upper receivers. So if you’re looking for something that might be close to universal, you’d be hard-pressed to find something quite like this.

This is a good 80% lower receiver branded for the renowned dealer, Brownells. This lower has been machined from 7075-T6 forged aluminum and comes equipped with a takedown lug pocket.

The broached magazine well helps in changing mags conveniently upon completion of this receiver. The receiver is compatible with a wide range of jigs so you don’t need to buy a new jig if you already have one.

The receiver is multi-cal and will fit any standard AR-15 Upper Receiver. It is available in hard-coat anodized and non-anodized variants so you may choose the one you like.

This version made from billet aluminum is fairly priced and bears the reputation of a renowned brand.

Who Will Use This Most

This will likely be put to good use by most AR-15 users who are looking for an upgrade from a default lower or as an addition to a rifle building project. Either way, this is a must-have accessory for all the right reasons. If you need an 80% lower receiver that will comply with state and federal laws, this could be what you need.

Bottom Line


Brownells' AR-15 80% Lower is hands-down one of the best factory replacement lowers you can find for an AR-15. Just add this on in a matter of minutes and you’ll be good to go for your next application.

Pros

  • Weather-resistant
  • Aesthetics are excellent
  • It will fit perfectly with most AR-15 rifles
  • Simple to install with the right kind of tools
  • Durable in construction and resistant to almost any damage

Cons

  • May not fit with some AR-15 upper receivers
  • May not be compatible with some caliber rifles

What Recent Buyers Report 

New buyers were quite happy with the lower receiver. They said this allowed for easier upgrading for most rifles. Some others were also able to use this 80 percent lower to add onto rifles they were building from scratch. They had no complaints about the fit and finish, nor did they complain about the installation of other lower receiver parts that go along with the lower itself.

Why it Stands Out to Us

This 80 percent lower is durable and can handle a great deal of damage if you somehow end up banging it around. It is also one of those lower receivers that will work with just about any lower receiver parts kit you choose. So, if you have a surplus of parts to make it work, this lower receiver will make the installation process a lot easier.

This 80% lower receiver has been machined from 7075-T6 forged aluminum and gives the user a chance to machine out the interior pocket themselves.

All the exterior machining has already been done and the user only needs to machine the hammer and trigger pocket for completion.

This receiver supports the 5.56 NATO cartridge and is compatible with all standard AR-15 uppers. It’s available in hard-coat anodized black and non-anodized variants.

The receiver is black in color and looks aesthetically pleasing. It also features a takedown lug pocket, which allows the user to take on an advanced AR build.

Who Will Use This Most

This will be excellent for users who are building an AR-15 rifle from scratch. So, if you need some parts to make the project a great success, an 80 percent lower will be one of the things you’ll need. Don’t forget, this also works with a variety of lower parts kits. If you know of any parts you need, be sure the kit you choose has them.

Bottom Line

The Matrix Arms AR-15 80% Lower is probably your best choice for a lower receiver if you plan on building a rifle from the ground up. At the same time, you’ll be able to build an AR-15 that will be legally compliant and a ton of fun to use once you’re finished.

Pros

  • Fits on a lot of upper receivers
  • It only takes a few minutes to install
  • Accepts a lot of lower receiver parts
  • Very durable and doesn’t damage easily
  • Compatible with .223 caliber AR-15 rifles

Cons

  • None

What Recent Buyers Report

As expected, a lot of new users were satisfied with this lower receiver. Most were owners of the .223 caliber version. They were able to fit this on a lot of the upper receivers with ease without having to make any alterations to the rifle itself. One user said he was able to add some drop-in parts to the lower and it operated like a well-oiled machine once everything was said and done.

Why it Stands Out to Us

This 80 percent lower is exclusive to those who use .223 caliber rounds for their AR-15 rifles. One of the things that stands out is that it’s made from high-quality polymer. In other words, it’s pretty durable. It can handle being thrown around, kicked around, or scuffing up. It won’t scratch and it surely won’t break easily. So if you want a lower receiver that will be hard to damage, you’d be insane to pass up the opportunity to give this a closer look.

Manufactured from high-grade polymer, this Gen 2 80% lower receiver from James Madison Tactical is easy to customize and install. This receiver is fairly priced as a polymer lower.

Machined to perfectly fit all AR-15 parts, the receiver features pre-machined areas such as buffer tube threads, the bolt release cavity, and the rear pivot pin. The receiver includes a trigger guard, as well.

Compared to other polymer lowers, this is extremely durable and in some cases comparable with an aluminum receiver. This is a multi-cal lower receiver, fit for most uppers of the AR-15 platform.

Just be sure to customize it properly, as the manufacturer doesn’t accept returns after any changes to the product!

Who Will Use This Most

This lower will be great for AR-15 owners that shoot .223 rounds. If you’re a hunter or a target shooter that is looking for an upgrade, you can start by upgrading the lower receiver. This little unit just might fit the bill if you’re doing a full-on upgrade of your rifle.

Bottom Line

The James Madison Tactical AR-15 80% Polymer Lower Receiver might be exactly what you need if you want something that is high in quality and can handle all kinds of lower receiver parts. If you want a lower receiver that will allow for superior functionality, this might be your cup of coffee.

Pros

  • Very durable
  • Simple to install
  • Fit and finish are excellent
  • Great for various applications
  • Excellent for building projects or upgrades

Cons

  • Some fitting may be required
  • Some of the detent holes are not completely drilled

What Recent Buyers Report

Most recent buyers were happy with the durability of this lower receiver. They managed to fire off as many as 1000 rounds before checking on it again. Sure enough, it could handle its own after so many gunshots. Aside from that, most users were able to fit it on many upper receivers.

Why it Stands Out to Us

Polymer proves itself to be one of the best materials you can use for a lower receiver, other than aluminum. It can take beatings and can hold its own after so many heavy-duty uses. On top of that, it’s also able to handle many lower parts that consist of the lower half of an AR-15 rifle. So if you need some drop-in parts, this 80 percent lower, in particular, can accommodate them.

Polymer80 offers this polymer 80% lower receiver as the best value for the money. The package includes an unfinished lower receiver along with a jig kit, which makes customization a breeze.

The jig kit also includes the necessary end mill bits and other components, so you don’t have to gather tools and resources.

Available in black, flat dark earth, and gray colors, this model offers multiple options to help you with the aesthetics of your rifle. It’s compatible with .223 REM and 5.56 NATO ammunition.

Who Will Use This Most

This will likely be used by those who are building out an AR-15 for the first time. If you’re not familiar with the process, it will take some time to figure things out. But if you need a lower to start with so you can add on the last 20 percent later, this 80 percent lower could be exactly what you’re looking for.

Bottom Line

The Polymer80 AR-15 80% Polymer Lower is a good start for those building out an AR-15 from scratch. Even if they’ve never done it before, this lower is the easiest to install. So if you want an add-on that will be the closest thing to a drop-in, this will be of good use.


Pros

  • Easy to install
  • Very well-machined
  • Durable construction
  • Accepts a lot of lower parts
  • Fits a lot of upper receivers just fine

Cons

  • Some have had issues with the rear takedown pins
  • Their jig set may not be the best in terms of quality

What Recent Buyers Report

A lot of recent buyers had nothing but good things to say about the lower receiver. They said they were able to drill the holes without any issues with oversizing or over-drilling. This lower receiver was easy to install, only taking as little as five minutes. One user said he used drop-in parts for his lower receiver and they worked like a charm without any jamming or reliability issues.

Why it Stands Out to Us

This 80 percent receiver stands out as one of the best for a .223 caliber AR-15. Plus, it comes unfinished, so you may want to stain it to however you want to ensure that it looks perfect with your rifle. This might also be lower that could mesh well with AR-15 rifles that are all part of a building project.

Anderson Manufacturing creates this unfinished lower receiver machined from forged 7075-T6 aluminum for improved durability and performance. The receiver is incredibly low on price respective to its quality.

Operations left to be completed include the fire control group milling, trigger and hammer pins, and the safety selector hole. The receiver is multi-cal when finished and offers extensive customization options to the user.

This receiver has been designed to mil-spec standards and is made in the U.S.A., so you can be sure of the quality. A jig is not included in the package so you’ll have to buy or arrange for it separately.

Some users have complaints with the Anderson Jig, so you might consider looking elsewhere or do some research before buying.

This receiver is perfect to create a rifle for tactical uses and target practice.

Who Will Use This Most

This can be used mostly by builders. If you’re looking for a simple add-on to your AR-15 rifle, this lower will do you some good. First and foremost, you’ll need to add on a finish that will fit your style and preference. Be sure you choose a finish that will make your rifle stand out.

Bottom Line

The Anderson Manufacturing AR-15 80% Lower is the one kind of lower you’ll want as part of your rifle building project. By the time you install this, you’ll have the makings of an AR-15 that can be a force to be reckoned with, either on the range or out in the field.

How Much Work is Involved to Install an 80% Lower?

Frankly speaking, 80% lowers are specifically for serious DIYers. If you love machining and are ready to put in some skills and effort, you ought to invest in one so you can have real satisfaction knowing the extent you went to in building your rifle.

Converting this piece of metal into the receiver you want can be done using a variety of different methods and tools. There are a ton of videos out there on the internet to help you out with this.

You can finish this project easily and economically if you have a manual end mill or a drill press. If you have a precision jig, this process will get easier. You can find a good precision jig online at many stores. 

If you are working with aluminum lowers, the process will be a bit time-consuming and difficult compared to working with polymers. The reason is obviously the difference in the hardness of these materials.

The time and effort to complete a task like this depends upon the tools you use (manual or automatic) and your skills.

How to Install an 80% Lower

Installing an 80% lower on your AR-15 is affordable and fun, but requires a good bit of work, so carefully follow the steps below and reference our video for assistance:

  1. Start with the magazine catch. Use a lower vise block to hold it in place. Locate your magazine release spring, place it into the hole, and cover it with the magazine release button, serrated side up. Press in and flip your receiver over and start threading. Be sure the catch won’t scrape against the receiver.
  2. Move on to the trigger guard assembly. Find the longer roll pin and trigger guard and depress the pin closest to the magazine well. Now, slip it in, ensuring everything is lined up, and use either a hammer or your fingers.
  3. Gather your bolt catch assembly parts and place the spring on the plunger and drop it in the hole above your magazine latch. Depress the catch, using a hammer if need be.
  4. Moving back to the trigger guard, attach the springs. Place the wide side down onto the trigger so the spring stays in position while you place the disconnector on the spring. Press down and you’ll see the trigger hole. You’ll place this assembly onto the receiver and put a pin through this hole.
  5. Place your assembly so the trigger will go through the receiver’s oval bottom. Match everything up so you can see the pinhole.
  6. Check the hammer and spring placement. Once the trigger pin is halfway through, cock the hammer down to ease the pressure. A brass punch may make this step easier.
    Important: Do not dry fire! You’ll damage the lower receiver if you do.
  7. Cock the hammer and insert the safety selector. Set the position to “fire” and place the safety detent into the hole opposite the safety indicator. Place the safety detent spring in the hole of the grip. Match the spring to the safety selector hole, ensuring it is still in “fire” position and screw in the grip.
  8. Install your rear takedown pin, placing the detent in back of your receiver and insert the detent spring.
  9. Place the buffer retainer and spring into the hole and screw in the castle nut.
  10. Put the end plate into the correct orientation and screw in the buffer tube, stopping before the tube reaches the retainer.
  11. Match the end plate with the receiver, screw in the last castle nut, and place the detent spring in first, followed by the detent, and lastly, by the pivot pin.
  12. Insert the buffer spring and slide on the stock. Pull your adjustment tab and move the stock inwards. You’re done!

Conclusion

An 80% lower receiver lacks the fire control group cavity which has to be drilled and machined in order to make it operational. These allow users to customize their AR-15 the way they want. Factors such as material, finish, brand, and aesthetics should be considered before buying. 

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