The 6 Best AR-15 80% Lower Receiver & Jigs

Comparison of The six best AR-15 80% lower receivers

PRODUCT	DETAILS
Our Top Pick	Precision Reflex – AR-15 A1 80% lower receiver	Made with high-quality forged aluminum Machined to mil-spec tolerances Looks good aesthetically A good value product	View Latest Price
Our Top Pick	Polymer80 – AR-15 80% polymer lower receiver & jig kit	Lightweight product weighing just 0.3 pounds Available in a variety of colors Easy material to work with Comes with a complete jig set including a high-quality jig	View Latest Price
	Anderson Manufacturing – AR-15 80% lower receiver	Very well-machined Durable material and construction Unfinished so you can finish it to your preference A low price receiver	View Latest Price

Building your own AR-15 is an appealing task for many shooters, as it lets you choose all the specific components to make a rifle that is unique and optimized.

Purchasing an 80% lower receiver can give you a fun DIY project to work on, that is, customizing and completing your very own firearm. As well as giving you a great sense of achievement, building from an unfinished receiver can save you money and can help you avoid some legal formalities.

Our list of the 6 best AR-15 80% lower receivers on the market

If you’re looking to build your own AR-style rifle then you will want to find the best ar lower on the market. To help you construct the very best AR-15 possible, I have reviewed and tested the 6 best AR-15 80% lowers in 2020.

All the products on this list are from trusted industry manufacturers and use the highest quality materials. I have put together the pros and cons of each product, allowing you to choose the one that’s best suited to you.

What is an AR-15 80% Lower?

80% lower receivers are partly finished lower receivers, which are essentially the fundamental building blocks of an AR-15. They require the user to do some milling and drilling to make them functional. As the name suggests, they are approximately 80% finished in the overall milling process.

• An 80% lower receiver will not yet have holes punched for hammer pins, the trigger, or the selector.
• The part where the trigger assembly is installed is solid and will need to be drilled and machined to convert it into a stripped lower receiver.
• As an unfinished item, it has not yet reached the stage of manufacture to be considered a firearm under the Gun Control Act of 1968 (GCA).
• 80% lowers are legal and are often referred to as “paperweights.” This means that they can be delivered straight to your house without the need to pay Federal Firearms License (FFL) fees.

Stripped Versus 80% AR-15 Lower Receivers

A stripped lower receiver is a serialized lower receiver entirely completed by the manufacturer. If you’re wondering whether you should purchase a stripped or an 80% lower receiver, here are the pros and cons of both, to help you decide what is best for you.

Stripped Lowers:

• Stripped lower receivers have been finished on a CNC machine, thereby providing tight tolerances and a precision fit and finish.
• With a stripped lower receiver you’re able to install your lower parts kit straight away without any milling work.
• A stripped lower is subject to all laws covering an FFL transfer.
• This means you’ll be required to complete the necessary paperwork before you can take possession of it.

80% lowers:

• An 80% lower gives you the personal satisfaction of creating and finishing your AR-15 build.
• While you won’t be able to install it immediately, completing an 80% lower is not that difficult and can be finished quickly and economically, especially if using a precision jig.
• You can purchase an 80% lower without the need for any FFL fees or paperwork.
• Purchasing an 80% lower will save you a bit of money, both in the sale price and in the FFL fees, however, the price difference isn’t huge.

The choice between a stripped lower and an 80% lower really comes down to how much personal input you would like in the finished product, and whether you want to undertake a DIY project or purchase a lower that’s already finished and is ready to be assembled.

Legal requirements for registering an AR-15 80% lower receiver

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. However, when constructing your gun from an 80% lower, you’ll need to ensure that you meet some legal requirements.

These are:

• The style of construction and configuration is legal within your state.
• You are making the gun for personal use only.
• You are legally eligible to own a firearm in your state/county/city.

As all states have different laws, it’s vital to check the laws of your specific state before constructing a firearm. As long as you meet the requirements above, you do not need to have an FFL to build a firearm.

As a private individual finishing an 80% lower for personal use, you do not need to register it or get a serial number. However, it is helpful to have one in case it gets lost or stolen.

If you intend to sell or transfer an AR-15 that you have built, then you will need to register it and obtain a serial number for it. The laws around sale and transfer are quite confusing so again, check your state’s laws first.

What Makes a Great 80% Lower Receiver?

There are a few factors you’ll need to carefully consider in your search for the best AR-15 80% lowers. These include:

Material

Lower receivers are generally made either of aluminum or polymer.

Aluminum

• Aluminum can be further divided into billet and forged, and into 6061-T6 alloy or 7075-T6 alloy.
• Billet is more of a general-purpose material.
• Billet is usually more expensive than polymer or forged options and can be heavier too.
• Billet is very easy to assemble, and more malleable.
• 7075-T6 is a higher quality aluminum and the most durable material for a lower receiver.
• Aluminum typically lasts longer than Polymer.

Polymer

• Polymer lower receivers are a relatively new option.
• Polymer is very affordable and normally comes with its own jig kit.
• Polymer is a softer material than aluminum, requiring less effort in the milling and drilling process.
• You can machine polymer components very easily, and the finishing process can be done with ordinary hand tools

Finish

80% lowers are generally type II or type III hard-coat anodized which makes them abrasion and corrosion-resistant. Many lowers have other kinds of finishes such as cerakote and duracoat.

There is much debate over whether it’s worth purchasing a lower receiver with a hard-coat anodized finish. When you’re milling and drilling the receiver to customize it, the inner layers of the metal, which are not anodized, will eventually become exposed. This means you’ll need to get the lower receiver anodized after finishing it. Therefore, I believe it’s best to go with non-anodized or simple aluminum 80% lower.

Brand

In my experience, I have found most small manufacturers to be hit or miss with 80% lower receivers. This is because these products often lack the precision of stripped or complete lowers.

Because 80% lower receivers need to be drilled and machined to be completed, they must have tight tolerances and precise working points to enable this. To ensure you do not experience any problems when constructing your new rifle, buy from a reputable and well-known industry manufacturer for confidence and peace of mind.

Aesthetics

Lastly, you will want to consider the color, design, and any engravings on the 80% lower you’re purchasing to ensure that it matches your aesthetic needs. Some receivers are available in a variety of colors, and some come with a spray-on finish in the color of your choice. Whilst this is not as important as the previous points, the aesthetics of your lower receiver will play a role in your satisfaction with the final product.

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How much time and effort does it take to assemble an AR-15 80% lower?

Assembling an AR-15 80% lower is not for first time DIYers. Nevertheless, if you have experience with DIY projects and love a challenge, then you should be able to complete your lower without too much struggle, or time spent.

Here are a few pointers to help you understand what to expect from the process:

• You can convert this piece of metal into a finished receiver by using a variety of different methods and tools, including tools you probably already own, like a drill and a router.
• To finish your lower as easily and economically as possible, it’s best to use a manual end mill or a drill press.
• A precision jig will make this process significantly easier.
• The process will take longer and may also be more difficult with an aluminum lower compared to a polymer lower. This is because of the difference in the hardness of the material.

The complete process of assembling and installing an AR-15 can be broken down into 3 phases:

1. Phase 1 is milling the 80% lower.
2. Phase 2 is installing the lower parts kit and buffer assembly into the lower.
3. Phase 3 is assembling with the upper receiver.

For a beginner, phase one can take between 2 and 3 hours, phase 2 will require 1 to 2 hours and phase 3 will need an additional 1 to 2 hours. That’s a total of 4 to 7 hours. Of course, for those with experience, the process will most likely be much quicker.

Considering these points, the time and effort it will take to complete your own AR-15 rifle will depend on the tools you use, for example, whether or not they are manual or automatic, along with your skills and experience in similar projects.

Tools needed to complete your AR-15 80% lower receiver

Before you start the assembly process, you will need to ensure that you have all the necessary tools to complete your lower receiver. What tools you’ll need will depend on whether your 80% lower receiver comes with a jig kit or not. In my opinion, purchasing an 80% lower with a jig set is the best option as it means you will already have many of the tools required.

That being said, some things may not be included in your jig kit which you will probably need. These are:

• A vise
• A drill press
• A hand drill
• Jig screws
• A set of hand files
• Some painter’s tape
• Precision needle files

If you do not have a jig kit, you may find that you already have some of the required tools laying around. In general, here is a list of components and tools that you’ll need for the assembling process of your AR-15.

• Set Screw Bolt Catch Pin
• Dowel Pin for Bolt Catch
• Pistol Grip Nut
• Pistol Grip Screw
• Allen Wrench
• AR-15 Jig
• End Mill for fire control pocket
• Drill Bit for the safety selector
• Drill Bit for trigger & hammer pinholes
• Drill Bit for pinholes & trigger hole

How to finish an AR-15 80% lower receiver

Here is a simplified step by step process to finishing an AR-15 80% lower receiver such as the Polymer80 lower using a drill press and a hand drill. Personally, I think these are the best and easiest tools for beginners to use to get started.

Of course, this process will differ slightly depending on the type of receiver you are using, the material your lower is made from, and the tools you are working with. For example, using a proper mill rather than a drill press will result in a much cleaner overall finish.

Take your time with the process and do not rush. You’ll be glad you paid the additional attention to detail once your lower is completed.

1. Secure the vise
   • Attach the vise to your drill press. Secure your lower to ensure it is held firmly.
   • With the jig properly aligned your 80 percent lower receiver, fix the jig tightly into your vice in the standard upright position.
2. Drill the side holes with your hand drill
   • Drill through the marked outside holes on your jig with the relevant drill bit. Specifically, these are specifically the trigger pin, hammer pin, and safety selector holes.
3. Drill out the fire control pocket with the drill press
   • The way I like to do this is with the plunge cut method. First, make successive dips and drills into the pocket.
   • Once you’ve plunge-cut enough, move on to using the action of the cross slide vise, with the drill press, to mill out the sides.
4. Drill out the trigger pocket
   • Take the jig out of the vise and flip it over so that the jig is upside down. Then vise it up in this position. Before you start drilling, it’s helpful to use tape in the vise to keep the guide secure.
   • Then, with your relevant drill bit, drill out the trigger pocket. The vise may need to be adjusted slightly to get the full pocket completed.
5. File it down
   • Using a drill press can result in the outcome looking a bit messy. However, you can file it down with a set of hand files to get a good uniform finish.
   • Additionally, using some precision needle files will help to smooth out and clean up the finish too.

Best AR-15 80% Lower Receiver

After testing and reviewing these six 80% lowers, I was most impressed with the Polymer80 80% lower receiver and jig kit. The easy-to-use material along with the included complete jig set certainly makes this receiver the most beginner-friendly. Out of all the lowers on this list, this one was the easiest to put together.

Along with its ease of use, this particular receiver rated high in durability, despite being polymer. It’s also very lightweight. As most AR-15 shooters choose to construct their own guns to have control over the construction and design of the firearm, the fact that the Polymer80 lower comes in various colors is very appealing.

I hope this article gives you a clearer understanding of the process of completing an 80% lower, as well as confidence in finding the best AR-15 80% lower for you.