The Ultimate AR-15 Lower Receivers Buyer’s Guide

Finding the best AR-15 lower will be a challenge. But it won’t be hard to find a great quality lower if you have a good idea of what kind of characteristics go into it. You may need one for the purpose of upgrading to a currently existing lower receiver. Or you’re probably building an AR-15 from the ground up and need one to start off the building project itself.

Either way, you have six of the best AR-15 lowers to choose from via the list below. Before we get to the list itself, we’re going to dive deep into what consists of a lower receiver and what the differences are between complete lowers versus stripped lowers (and comparing the both of them to 80 percent lowers).

The lower receiver is considered to be the most important and primary part of a weapon. Federal law, customization capabilities and price of the AR-15 have all been an important factor in the story of aftermarket AR-15 lower receivers. Here we’ll be talking about the AR-15 lower receivers and their place within the rifle.

We’ll also talk about the different types and components of a lower receiver. You will also learn to install an AR-15 lower receiver to build up your weapon properly. So let’s get started.

Comparison Chart of the Best AR-15 Lower Receivers

PRODUCT DETAILS
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PSA AR-15 Complete Moe Ept SBA3 Lower

  • Includes a standard carbine buffer.
  • Made from high-quality 7075-T6 aluminum.
  • Best overall for complete AR-15 lower receivers.
View Latest Price
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PSA AR-15 American Flag Engraved Stripped Lower

  • Includes an engraved American flag.
  • Best overall AR-15 stripped lower receiver.
  • Made from high-quality 7075-T6 aluminum.
View Latest Price
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PSA AR-15 MOE EPT Lower

  • Made from high-quality aluminum.
  • Includes Magpul MOE stocks and grips.
  • Runner-up for best AR-15 complete lower.
View Latest Price
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Anderson Manufacturing - AR-15 Stripped Lower Receiver

  • Best fit for 5.56 and .223 caliber rifles.
  • Runner-up for best AR-15 stripped lower.
  • Made from high-strength 7075-T6 aluminum.
View Latest Price
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PSA AR-15 Freedom Classic Lower, Flat Dark Earth

  • Standard carbine buffer.
  • Best AR-15 complete lower for the money.
  • Made from high-quality aluminum forgings.
View Latest Price
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Spikes Tactical - AR-15 Stripped Lower Receiver With Color Fill

  • Best AR-15 stripped lower for the money.
  • Anodized coating added for extra durability.
  • Made from high-quality 7075-T6 aluminum.
View Latest Price

What Makes a Gun a Gun?

In simple terms, the receiver of a weapon is the part which houses all other primary internal components (hammer, bolt and action). The receiver is also threaded to receive the barrel and the stock of the weapon.

According to firearms terminology and the law, the receiver itself is the firearm. According to the US law, a receiver has to be serialized and its sale and purchase are strictly regulated by law.

The main reason behind this is that the receiver is what combines all the essential working parts of a weapon and makes it capable to fire. The threads on the front and rear house the barrel and the stock. The base houses the magazine catch and trigger assembly, and the top houses the bolt, charging handle and ejection mechanism.

Talking specifically about the AR-15, this weapon has a unique receiver design. The AR-15 features a receiver which is divided into two parts, namely the ‘upper receiver’ and the ‘lower receiver’. 

This unique split design of the AR-15 makes it suitable for a number of aftermarket customizations related to aesthetics, functionalities and even caliber. More on that later.

The upper and lower receivers of the AR-15 are held by two pins which makes it almost effortless to separate the receivers for cleaning or customization.

In regards to the AR-15, the lower receiver is the part that has to bear a serial number and purchasing one requires an ID and a background check. An AR-15 lower receiver can only be sold by a licensed firearms dealer.

A complete or stripped lower receiver requires a federal firearms permit to purchase.

Buying all other parts of a weapon except the receiver is just like buying candy. No ID, no background check, no whatever. Just pay the price and you’re done. That’s because every other part of a weapon is practically useless without a receiver.

What Are The Components of a Lower Receiver?

There are key components that comprise a lower receiver. Whether you’re getting one that’s fully assembled or completely stripped for the purpose of assembly, you need to know what’s included. Keep in mind that not everything will be included in some lowers (stripped lowers won’t include any parts whatsoever).

To state it in a single sentence, the lower receiver of an AR-15 contains the fire control group. The fire control group includes the trigger, disconnector, hammer, magazine catch and the fire selector. Or in simpler terms, the lower receiver houses the trigger assembly and the magazine.

The lower receiver is secured to the upper receiver by two pins which can be easily removed for disassembly. This split design helps in customizing the upper receiver with ease.

If you are looking to create an entire lower receiver by yourself, you can buy an aftermarket lower parts kit for an AR-15 rifle. If you are using an unfinished receiver, you’ll have to machine all the slots to fit these parts in. If you are using a stripped one, all you have to do is simply drop in these parts.

A lower parts kit includes a magazine catch, bolt catch, pivot pin, fire control group, trigger guard, selector, grip, and pins. Further, you will need a complete rear stock and a spring assembly. Now, here is a list of what components are found in AR-15 lower receivers:

Trigger Assembly

The trigger assembly is probably one of your most vital components in a lower receiver. This will contain your trigger, the housing, and the pins and springs that hold it all together. Without this, your rifle will obviously be useless. You cannot fire off any shots without a reliable trigger installed.

Magazine Catch

No rifle is complete without a magazine catch. Your mags need a place to go. So why not find a magazine catch that will be reliable in holding the magazine together while you’re using your AR-15? This makes sure that the magazine stays in place in the mag well and won’t wiggle on you.

The Czech MK3, a derivative of the ar15

Pistol Grip

Yes, the pistol grip will be part of a lower receiver assembly. Especially if you’re purchasing one that is considered fully assembled. The pistol grip serves the purpose of providing you with better stability. Some will use it and some will not. But don’t write off the pistol grip as a useless accessory. If accuracy is your thing, then stability will definitely be important.

Buttstock

Some of the assembled lower receivers will include a buttstock that is attached. It goes without saying that the buttstock is an important part of the lower receiver for several reasons. It gives you all kinds of support and stability. With that solid support, you’ll be able to get a great deal of accuracy by way of stable shooting. Most of the buttstocks will be made from synthetic materials. That makes for reduced recoil, reduced shock, and even better comfort.

Complete vs. Stripped vs. 80 Percent Lower Receivers - Similarities, Differences and How to Choose

Now, we’ll be taking a look at a triple threat comparison of how the following three types of lower receivers stack up. We’ll be looking at complete receivers and compare them to stripped and 80 percent lowers. We’ll take a look at the similarities, differences, and how you can choose one of these three for your own use.

Basically, these three are the different stages of a receiver from start to end. These variants differ regarding federal regulations, price, customizability and ease of installation.

Before you choose this lower receiver, you need to be aware of a few things. First, you’re obviously going to need the right kind of parts to build it from the ground up. This includes finding a separate trigger assembly, magazine catch, and all the other components that make it all work. Second, you’ll need to file the appropriate paperwork in accordance with federal laws and regulations. Let’s start off by discussing the complete lower receiver.

Complete Lower Receivers

Your complete lower receivers will cover the entire lower half of the AR-15 rifle. On top of that, complete lowers will already have the included parts assembled. These will come in handy if you’re looking for a simple upgrade or if you’re doing your first ever AR-15 rifle build.

Since complete lower receivers will be assembled, they are considered firearms in accordance with federal regulations. This means that there are sales restrictions that are in place, especially in certain states like California. 

If you need to choose this type of lower, the first thing you need to do is make sure that you are legally able to purchase and own one in accordance with the gun laws in your locale and state. This will save you a lot of legal headaches that may arise from unintentionally breaking any laws or regulations. 

A complete AR-15 lower receiver, as the name suggests, is a finished ready-to-install product. It includes the trigger assembly, magazine catch, grip and sometimes the stock. You don’t have to put anything extra in it to make it work. All you have to do is simply attach it to the upper receiver and you’re ready to go.

Complete lower receivers require a federal firearms license before purchase. Since they are already ‘complete’, they are obviously more pricey than their counterparts.

Stripped Lower Receivers

Nine times out of ten, a stripped lower receiver will have no components at all. All it will be is the framework itself. It will be your responsibility to assemble it piece by piece to ensure that it is in working order.

How it compares to complete and 80 percent lower receivers is that it comes with a solid aluminum or steel frame. And that’s where the similarities end. The major difference between stripped lower receivers with complete and 80 percent lowers is obvious, but you’ll know it when you see it. 

A stripped AR-15 lower receiver is more in the middle stage of manufacturing. A stripped lower receiver has all the slots and holes precisely built in it using CNC machining. This means you can simply drop in your lower parts kit and you’ll have your lower receiver ready.

Stripped receivers are serialized. All the federal firearms laws and regulations as well as state laws and all other necessary paperwork apply.

80 Percent Lowers

Your 80 percent lowers are more for the builders themselves. The goal here is to finish up the final 20 percent to make it complete. One of the tools you’ll need to put to good use in order to make it complete is a good ol’ fashioned precision jig.

These receivers will not have assembly parts in place. It is for this reason that these lowers are not considered firearms in accordance with ATF regulations. This has more similarities with stripped lower receivers than complete ones. The reason is obvious. An 80 percent receiver is simply just the framework.

The only difference between an 80 percent and stripped receiver is the coverage area. Once again, the difference between an 80 percent lower and a complete type is the assembly. An 80 percent lower has no parts, a complete lower does.

An 80% lower receiver, also termed as ‘unfinished receiver’ or ‘blank’, is the main buzz nowadays.  An 80% receiver is an unfinished AR-15 lower receiver which does not require any serial number. That means that it is not regulated by the law. You can buy or sell one without any background checks, license or permits.

But this great advantage also has a drawback. The buyer needs to machine the receiver to make it usable. This requires proper machining and gunsmithing skills. An unfinished receiver is obviously inexpensive, customizable and doesn’t need a permit. However it still requires an expert as well as the proper machining equipment.

Quick Take - The Best AR-15 Lower Receivers

Reviews of the Best AR-15 Lower Receivers

Below is a list of the six best AR-15 lowers that are currently on the market. As you look through every single one of them, it is important to make the determination of which lower receiver will be best for you. As you complete the process of elimination, you’ll now make a decision based on the characteristics and features.

If you have a list of what you want in a dream lower receiver, it’s important to find one that’s close enough. Close enough is a lot better than nothing at all. Now, let’s get to the list by kicking off with our “best overall” choice:

Pros

  • Construction is Solid and Durable
  • Pistol Grip is Great for Better Stability
  • No Malfunctions After 500 Rounds Fired
  • Completely Assembled From the Ground Up
  • Recoil is Less Noticeable Once Installed On AR-15 Rifles

Cons

  • Trigger Pull is a Bit Heavy
  • Safety Selector Switch Might Be a Little Crooked
  • Some Have Complained About the Quality Feeling Cheap and Flimsy

What Recent Buyers Report 

Recent buyers were able to easily install this lower receiver on their currently existing rifles. Some of them were also building their first AR-15 rifle from the ground up. It was easier for them to choose this since they didn’t have an advanced level of gunsmithing skills.

Why it Stands Out to Us 

The lower receiver itself is tough all over and has all the parts in place to make it work like a regular lower receiver. For first time builders, this will be an excellent starting piece to what might be a fully functioning force to be reckoned with. It’s durable, has all the right parts, and the buttstock is quite comfortable once you’re able to use it. 

Who Will Use This Most 

This is a lower receiver that will be best used for those who want a complete upgrade from a stock lower. Other users will probably be those who are building their first ever AR-15 from start to finish. Either way, it’s easy to install and easy to use thanks to it being completely assembled.

What Could Be Improved and Why 

One of the things that should definitely be improved is making the trigger pull weight a lot lighter. Some have complained about the pull weight being too heavy. Don’t you think 8 or 9 pounds of pull weight is a little much? We like to think so. 

Bottom Line 

If you’re looking for the best of the best when it comes to AR-15 lower receivers, then the PSA AR-15 Complete Lower Receiver with Tactical Brace will definitely be your go-to choice. Why waste time tracking down all the lower receiver components when you already have them here in one complete assembly?

Best AR-15 Stripped Lower Overall:
PSA AR-15 American Flag Engraved Stripped Lower

Pros

  • Super Durable Construction
  • Finish is Nice and Sharp, Makes it Look Really Good
  • The Engraving Was Spot On, According to One User
  • Works Perfectly With Various AR-15 Builds and Calibers
  • Includes “Fire”, “Safe”, and “Pictogram” Markings for Easy Identification

Cons

  • None

What Recent Buyers Report 

A lot of buyers were those who wanted to build their AR-15 rifle from the ground up. They were impressed with the overall construction and finish. It’s quite durable and has the potential to withstand a lot of heavy duty activity, according to one user. 

Why it Stands Out to Us  

No DIY project can start without a great stripped lower. The reason why it sticks out is not just the durability and construction. To us, it’s the finish and the specialized engraving. Nothing is more American than a lower receiver that is not only highly functional and durable but also is sleek and sharp in terms of looks.

Who Will Use This Most 

Obviously, this will likely be used by those who are DIY builders. Some of them have had previous experience with building AR-15 rifles before. So this will be used if they are building their second or third rifle build from scratch.

What Could Be Improved and Why 

While there are no obvious cons to point out, one thing we need to make sure you understand is that no receiver is complete without the right kind of parts. So be sure to find the right trigger assembly, mag catch, and pistol grip among all the other components you need. 

Bottom Line 

If you’re looking for a stripped receiver that is the best in quality and aesthetics, the PSA AR-15 American Flag engraved stripped lower receiver might be exactly what you’re looking for. What better way to start off a DIY project than finding a lower that is built to last and built to fit most AR-15 rifle parts.

Best AR-15 Complete Lower Runner-up:
PSA AR-15 MOE EPT Lower

Pros

  • Very Lightweight and Durable
  • Excellent for Upgrading Purposes
  • Trigger Quality is Nice, Pull Weight is Decent
  • Matches Perfectly With Most PSA Brand Uppers
  • Tested Across Many AR-Style Rifles, Works Perfectly

Cons

  • Pins Might Be Loose and Need to Be Tightened
  • Some Are Not Satisfied With the Trigger Pull Weight
  • One Complained About the Stock Being Loose and Sloppy

What Recent Buyers Report 

A lot of recent buyers were more of the upgrading type as opposed to do-it-yourself folks. Since it’s a fully assembled lower receiver, it will definitely be a step up from your factory or stock lowers that have a heavier trigger pull. According to one user, the trigger pull was a little lighter than his previous lower.

Why it Stands Out to Us  

This is a lower that is easier to use and easier to grip. That alone equals better odds of hitting your targets accurately. If easier is better, then it’s definitely going to be better for those who have little to no experience firing an AR-15 rifle. Other than that, it’s a lightweight and durable unit that is built to last and ready to take on some heavy duty applications.

Who Will Use This Most 

This will be used mostly by those who will look to upgrade their AR-15 rifles. Especially those who are getting tired of using the same old ineffective lower. If you’re looking for a lower that has a better trigger assembly and will give you even better support, this is the lower receiver that will work best for you.

What Could Be Improved and Why 

One improvement that might be suggested is the possibility of making the trigger pull weight a little lighter. This time, by a little bit. A good ideal pull weight should be around 3.5 to 4 pounds at most. That will not only make for easier and quicker follow-up shots, but it will lessen the risk of fatigue during extended range sessions.

Bottom Line 

If you’re looking for a fully assembled lower that will be easier to use than standard lowers and won’t give you any grief like what a stock lower does, then the PSA AR-15 MOE EPT Lower might be just right up your alley. This is definitely the one lower you’ll want to upgrade to if you’re looking for something lightweight, durable, and with a lighter trigger pull. 

Best AR-15 Stripped Lower Runner-up: 
Anderson Manufacturing - AR-15 Stripped Lower Receiver

Pros

  • Very Sturdy Construction
  • Super Durable in Strength
  • Affordable For Most Budgets
  • Excellent For Do-it-Yourselfers
  • Finish Makes the Aesthetics Sharp and Sleek

Cons

  • May Not Work With Some AR-15 Uppers
  • Some Adjustments and Modifications Might Be Needed Before Assembling
  • Rear Takedown Holes Might Be a Little Smaller Than Expected, It Makes Fitting the Pin Rather Difficult

What Recent Buyers Report 

A lot of recent buyers liked this lower receiver. Some of them have had their lower components handy by the time this was shipped to them. All they had to do is fit each component on where it was needed and it was done in a matter of hours. One remarked that the cornerstone of any good AR-15 build is a good lower receiver, and of course, this stripped lower is the best example of that.

Why it Stands Out to Us  

This is one of the toughest, most durable stripped receivers that are currently on our list at this point. If you’re planning to build an AR-15 rifle that will get the job done while taking on the numerous bumps and bangs that would otherwise damage other lower receivers, this is the lower you want to go with.

Who Will Use This Most 

This will be used by shooters who want an AR-15 that’s built to last. We’re talking years or even decades. So it’s important to find a lower receiver that will have that potential. At this point, it’s this stripped lower that fits the bill. 

What Could Be Improved and Why 

As far as improvements go, there definitely needs to be adjustments to the takedown pin holes. Make them at a size where they can accept all kinds of takedown pins. The holes right now are either making some pins not fit or they appear loose and may need to be refit. This improvement will lessen that hassle.

Bottom Line 

If you’re looking for a stripped lower receiver that will stand the test of time and the test of impact, then you’re looking at the one that will best fit you perfectly. The Anderson Manufacturing AR-15 Stripped Lower might be right up your alley if you’re looking for a lower that will handle all your much-needed components while making your rifle much more reliable and useful in every application.

Best AR-15 Complete Lower For The Money:
PSA AR-15 Freedom Classic Lower, Flat Dark Earth

Pros

  • Excellent for Both AR-Pistols and Rifles
  • Easy to Install, Especially For First-Time Users
  • Super Durable and Excellent Construction
  • Flawless Operation Even Through 1500 Rounds
  • The Safety and Trigger Switch Have An Excellent Feel

Cons

  • Pins May Not Stay in Place Easily
  • Some Report the Stock Being a Little Sloppy
  • Trigger Pull Might Be a Little Rough and Heavy For Some

What Recent Buyers Report 

A lot of happy buyers. It was not only affordable, but it’s quite usable for most of them. They were able to install this in a matter of minutes and were ready for action the same day. This is more of an upgrade lower receiver rather than something that can be used for do-it-yourself AR-15 builders.

Why it Stands Out to Us  

For a budget lower receiver, this is pretty solid for a completely assembled receiver. Indeed, it has all the fixings you need to make sure that this puppy is fully functional and always ready for whatever the application is. Other than that, it’s a pretty rugged unit that will definitely last you a long period of time.

Who Will Use This Most 

This will be used by budget shoppers who are looking for an upgrade rather than a do-it-yourself project. Since the parts will already be assembled, this will save someone even more money and time rather than try to figure out where to find the parts they need and how much it’s going to cost them.

What Could Be Improved and Why 

One of the things that could improve is the possibility of making sure the pins stay in place for most of the key components. This could mean re-sizing the pins or the holes that hold them together. Making sure that your components are secure is key since loose parts might pose a potential danger to your safety.

Bottom Line 

If you’re looking for a completely assembled receiver that won’t suck the life out of your bank account, this PSA AR-15 lower receiver might be exactly what you need, if you’re simply just looking to upgrade the lower receiver on your rifle. It’s got all the right parts that are durable and reliable while allowing you to save all kinds of cash in the process.

Best AR-15 Stripped Lower For The Money: 
Spikes Tactical - AR-15 Stripped Lower Receiver With Color Fill

Pros

  • Very Excellent Quality
  • Excellent For the Price
  • Smooth is Sleek and Sharp
  • Excellent For AR-15 Builders
  • Functions Properly After Thousands of Rounds, No Issues To Report

Cons

  • Might Not Fit With Some Upper Receivers
  • Some Adjustments and Fitting Might Be Required
  • Some Have Complained About the Quality Not Being as Good as Expected

What Recent Buyers Report 

A lot of recent buyers were looking for a really good stripped receiver that would work with their do-it-yourself project. In fact, this was more of a starter lower for those who wanted to give building an AR-15 a shot. They were happy with the overall quality and were able to easily fit most of the components that you need in order for the lower to function.

Why it Stands Out to Us  

A stripped receiver that is solid in construction and affordable in price. What more can we ask for? Especially when you want to start a building project while you’re trying not to spend too much money. This has the potential to fit really well with either standard AR-15 rifles or pistols.

Who Will Use This Most 

This will be used by the budget do-it-yourself builders. Since they’ll be spending a good amount of money on separate components, they’ll definitely look for a lower that will work to their advantage financially. Expect first-time buyers to consider this lower as a possible option.

What Could Be Improved and Why 

One of the things that might improve is making some of the edges a little smoother. This way, it will prevent sharp edges which might result in cutting your hands or clothing. Some sanding might be the solution to this issue. But why waste time doing it when you have a rifle or pistol to build? 

Bottom Line 

If you’re planning on building our an AR-15 rifle or pistol and need a lower receiver that won’t break the bank, this stripped receiver by Spikes Tactical will be your kind of lower that will help you make your building project a reality. It’s durable, will fit all the components you need, and won’t steer you wrong once everything is put together. 

Factors to Look For

Before choosing a complete lower receiver for your AR-15, there are several factors you must consider.

Material

AR-15 lower receivers are generally manufactured from aluminum or polymer. Basically two different types of aluminum (6061-T6 and 7075-T6) can be used to machine or forge these receivers.

The 6061-T6 aluminum is generally used in the manufacturing industry for everything from vehicles to utensils and firearms. It has superior workability characteristics and hence the use.

The 7075-T6 aluminum on the other hand is aircraft-grade aluminum which makes it more durable and tough as compared to 6061-T6 aluminum.

Polymer lower receivers on the other hand are lightweight but not so durable in the long run. Plus they are more susceptible to damage and wear ‘n tear.

Type: Billet or Forged   

Forged is the traditional style of manufacturing receivers where the metal is melted and shaped using hydraulic hammers. It’s simple, effective and it’s the method the U.S. military chooses for their M16/M4 lower receivers.

On the other hand billet receivers are machined and hence bear cleaner lines and are heavy duty. Plus they have a unique and cleaner look. Receivers made from polymers are generally injection molded, but type is not much of a concern with polymer lower receivers.

Finish: Hardcoat anodized, Cerakoat, or None

If you choose to buy an aluminum complete lower receiver, you must consider its finish. Aluminum for firearms is generally hardcoat anodized (type III) which is similar to standard anodizing (type II) but provides a superior and more resistant coating to the metal.

Additionally, hardcoat anodizing is also the preferred military standard. Apart from this, you can also opt for a cerakoat or duracoat finish to impart durability and longevity to your complete lower receiver. It is generally not recommended to buy lower receivers with no coating and the reason is pretty obvious.

Hardcoat anodized receivers generally come in black whereas duracoat- and cerakote-finished lower receivers are available in a wide range of colors.

Manufacturer and Quality Control: Precise holes, roll pin holes, magwell

Before choosing a lower receiver for your AR-15, you must consider the trust and reliability associated with the manufacturer. Quality control is an important aspect while purchasing a lower receiver.

You need to make sure that all the holes are placed precisely and are perfect in shape. The magwell has to be aligned properly and is perfect in size. Plus all the components such as the trigger, safety and selector switch must work properly.

Choosing a lower receiver from a renowned manufacturer eliminates the possibility of getting a defective product. Additionally, renowned manufacturers generally offer a limited or lifetime warranty or guarantee so you always have your back covered.

Aesthetics

Last but not the least, you want your rifle to look cool. So you must take note of the aesthetics of the complete lower receiver you are going to buy. From logo and color to any other engravings on your complete lower receiver, you should consider browsing around to find the design you like.

Important Info

Before wrapping this up, we should mention something as you are looking for an AR-15 lower. It’s vital to know which one you’ll need to use for your own intents and purposes. The reason why is because due to strict gun laws, you might be allowed to purchase and own one type of lower while you might not do so with other types. For example, if you live in the State of California, an 80 percent lower or stripped lower might be the only type you might be able to purchase.

Always err on the side of caution and research the gun laws in your jurisdiction (as well as federal laws). Doing so will save you from future legal headaches. If you order through a vendor online, they will explicitly inform you whether or not your lower of choice will be available to residents of certain states. 

It is important to note here that a receiver you manufacture on your own from a blank does not need a serial number when it is finished. However, you are not allowed to sell, transfer or gift that weapon to anybody unless you apply for and get a serial number after proving it to the authorities that you manufactured the lower receiver yourself. Please consult a legal advisor before transferring or selling it.

How to Install an AR-15 Lower Receiver

Okay, so here we’ll be digging deep into how to setup and install a lower receiver to the AR-15. This installation guide is primarily focused on installing stripped lower receivers. We’ll leave aside 80% receivers for now because they need to be machined first.

If you are looking to install a complete/finished receiver, please skip directly to step number 9.

Before we get started, let's first gather the tools and equipment we’ll be needing for this task:

  1. Stripped Lower Receiver
  2. AR-15 Lower Parts Kit
  3. Brass Pin Punch Set
  4. Rubber/Plastic ended hammer to push the pins without damaging the finish.
  5. C-clamp/Pliers to drive pins in.
  6. Hex-key set (preferably long arm)
  7. Utility Knife/blade or a Pen.
  8. Masking Tape
  9. Small Wooden Plank

Assembling an AR-15 lower receiver is a combination of several different steps. These include assembling the:

  • Trigger Guard Assembly
  • Magazine Catch Assembly
  • Bolt Catch Assembly
  • Trigger Assembly
  • Hammer Assembly
  • Selector and Pistol Grip Assembly
  • Buffer Tube Assembly

Step 1: Installing the Magazine Catch Assembly

Install the magazine catch in the wide hole on the left-hand side of the receiver. Insert the magazine catch spring from the right side of this hole.

Now place the magazine release button on the spring and screw the catch from the left side using a hex wrench.

Depress the magazine release button and further screw the catch so it fits flush into the assembly.

You can now insert a magazine and press the button to check if it works properly. 

Step 2: Installing the Trigger Guard

The next step is installing the trigger guard. Take the trigger guard and press the detent on the front part of the receiver base (just where the magazine well ends) so it snaps in.

Support the bottom flange of the trigger guard with a block of wood, rubber or plastic.

Now push the roll pin slowly in the rear of the trigger guard using the hammer and pin punch. Now you’re done with the trigger guard.

Step 3: Installing the Bolt Catch

Cover the area between selector switch and bolt catch with some tape to prevent any scratches.

Install the bolt catch retaining pin in the first hump. Now install the bolt catch spring into the hole on the left side of the receiver, and install the bolt catch plunger on top of it.

Now install the bolt catch in the receiver and drive the pin the rest of the way in.

Step 4: Installing the Front Takedown Pin

Insert the spring and the detent into the small hole of the receiver.

Compress the spring and the detent with a knife or the pens’ nib and slide the takedown pin into the hole.

Step 5: Installing the Trigger Assembly

Install the trigger spring onto the trigger with ends of the trigger spring facing forward and under the trigger.

Now push the disconnector spring inside the trigger all the way down.

Then position the disconnector on top of the spring and push it into the receiver. Now insert the trigger retaining pin using the hammer through the trigger, receiver and the disconnector.  

Step 6: Installing the Hammer Assembly

Put the spring on the hammer with ends of the hammer spring facing away from the hammer strike face.

Now insert the hammer into the receiver and punch to fit the hammer retaining pin into place. The ends of the hammer spring will rest on top of the top of the trigger pin.

Step 7: Installing the Safety Switch Selector and Grip

Cock the hammer back, hold it in place with your hand and install the selector switch through the hole, keeping it in the ‘safe’ position. Hold it and verify if the safety is working.

Now install the selector detent pin with the pointed end towards the selector and continue pushing the spring into the bottom hole of the receiver in the area where the grip is installed.

Insert the pistol grip screw with the washer inside the pistol grip and tighten it firmly to the receiver.

Step 8: Installing the Buffer Tube Assembly

Put the buffer retainer spring into the rear end of the receiver followed by the retainer. Now screw in the buffer tube and when it reaches the retainer pin, push the pin down using a screwdriver and screw the tube further so the retainer gets locked.

Insert the takedown pin detent with the point facing the takedown pin into the small hole on the backside of the receiver. Then insert the takedown pin behind it. Now tighten the castle nut to hold everything in place.

Install the buffer spring into the buffer tube and keep it in place using the retainer pin.

Step 9: Joining the Lower Receiver to the Upper

If you have a complete AR-15 receiver, you can jump directly to this step. Follow this step backward first if you need to disassemble the upper and lower receivers first, for replacing a complete lower receiver.  

Force the lower and upper receivers in place so they tightly fit in. Now push in the takedown pin and pivot pin and you’re good to go.

The takedown pin can be found on the upper part of the lower receiver just where the buttstock begins. The pivot pin is located on the upper front part of the lower receiver where the unit is pivoting.

Perform a function test by checking the chamber, checking the safety, check the trigger, cycle the chamber and check the trigger reset. If everything works perfect, congratulations, your AR-15 is ready to fire.

Conclusion

The best AR-15 lower is out there. Whether you want a complete lower for an upgrade or a stripped lower for a building project, you want something that is durable, reliable, and will definitely serve you in the long run. Depending on what you go with, make sure that everything works right down to the most basic components. 

According to weapon terminology and the law, the receiver is itself the firearm. Federal laws require a receiver to be stamped with a serial number and its sale and transfer are regulated by law. The AR-15 features a unique split design being divided into upper and lower receivers.

The lower receiver holds the magazine catch, trigger, trigger guard, bolt catch assembly, selector, safety and the pistol grip. A lower receiver can either be complete, stripped or an 80% receiver. Due to the modular design, it is fairly easy to replace the lower receiver of an AR-15. Putting in just minimal effort and tools.  

People Also Ask

The following are three of the most frequently asked questions that are typically asked by new buyers. It is important that you refer to these questions and answers as an additional guide that will help you find a good AR-15 lower for your current rifle or building project. Here are the following answers:

Does an AR Lower Affect Accuracy?

It won’t affect your accuracy directly. Some major components like the barrel might affect your accuracy more. But your lower receiver or any of the components included are basically responsible for the firing aspect of your rifle. 

Do You Need an FFL to Buy a Stripped Lower Receiver?

A stripped lower receiver does not include any assembled parts like a trigger assembly or any other components. However, you still need to purchase one through an FFL-licensed dealership. 

Are 80 Percent Lowers Illegal?

Short answer: no. Long answer, since they are not complete lowers with no components, they are not considered a firearm. This also means that you won’t need to file any paperwork that you would otherwise need to file if you ordered a complete or a stripped receiver. 

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