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Finding the best AR-15 lower receiver is one of the first steps in building an AR-15 rifle. You might see a complete rifle you want to clone, a great upper, maybe a barrel, but before you get too deep into your build, you need to pick out your lower.
But picking the wrong lower could mean the difference between having the AR of your dreams or having one that malfunctions when you need it most.
Yikes…
Thankfully, you’re in the right place. We go over everything you need to know to find the perfect AR15 lower for your needs.
Contents
- The Best AR Lowers
- The Top Brands for AR15 Lowers
- Things to Consider When Buying an AR-15 Lower
- Billet AR-15 Lower vs Forged Lower: Which is Better?
- What Is a Stripped Lower Receiver?
- What Is a Complete Lower?
- Stripped vs Completed – Which is Right For You?
- Where to Buy an AR-15 Lower Receiver
- What Calibers Can Be Used in AR15 Lower
- Frequently Asked Questions
- Further Reading
- Our Recommendation – PSA AR-15 “Stealth” Stripped Lower Receiver
- References
The Best AR Lowers
1 – Top Pick – PSA AR-15 “Stealth” Stripped Lower Receiver
This simple yet powerful forged 7075-T6 aluminum lower receiver by PSA is a great AR-15 lower for a completely customizable AR-15 build.
It is made to mil-specs and has no roll mark on the left side, just the caliber, model and serial (starts with PA). This means that you can put your own logo on it to make your AR-15 even more “yours” and personalized.
This lower has a Black Hardcoat Anodized finish and works for a variety of calibers, making it a very versatile piece of equipment to start building your perfect AR-15.
In fact, this is a very good all-rounder Lower receiver that comes from one of our favorite suppliers, Palmetto State Armory who have a great reputation for making high-quality products that are still affordable. If you do have an issue or question, there support staff are extremely knowledgable and easy to reach.
And if you’re looking to get an AR-15 kit made for the Stealth, you’re in luck…
PSA also has this great Magpul Moe Lower Build Kit in Black that is on sale right now (until December 13, 2024) for less than half its original price!
This kit includes everything you need to completely assemble the lower receiver for your perfect AR-15. The parts are all made in the US by some of the best companies in the industry and include mil-spec MOE Stock and grip from Magpul Industries, as well as a mil-spec buffer tube assembly set and PSA Classic Lower Parts Kit from Palmetto State Armory.
With this set, you get everything to build a complete lower receiver in one package and don’t have to worry about buying any extra bits and pieces!
I’ve used both in the past, and of the many AR-15 builds I’ve done, I found that PSA products are the highest quality and the easiest to assemble, period.
***Update***
The PSA Stealth is currently on sale until December 13, 2024. Make sure to use the link below to get the savings before the price goes back up.
2 – Runner Up – Brownells BRN-15
This Brownells M4 lower receiver, like most others on this list, is a forged 7075-T6 aluminum lower receiver, built to mil-spec. What makes the BRN-15 lower an amazing lower is the price and the quality.
Made in Iowa, in the heart of Midwest corn country, this AR-15 stripped lower is as standard as standard can be, but the quality of the workmanship and low price make it enticing.
To give you some context, you’d have to pay about 40%-50% more to find another lower of this quality.
Brownells is one of the best gun stores in the world with a staggering supply of unique rifle choices, so you really can’t go wrong with one of their lower receivers. They also are legendary for their customer service and order turn around time, so when most people are twiddling their thumbs waiting for the package, you’re already on the range.
Simply put, this standard but high-quality AR-15 lower receiver has everything you need and comes at a low price because it doesn’t have any unnecessary extra bells and whistles like most brands. This makes it the perfect starting piece to build your very own AR-15, just as you like it.
This AR-15 stripped lower receiver is precision machined to final dimensions, which are compatible with the majority of mil-spec AR-15 components on the market. This means you are free to choose your other AR-15 components without having to worry about compatibility with your lower receiver.
It comes with a matte black, Type III hardcoat anodized finish, making it look very sleek, military-like, and almost elegant.
As an experienced hunter and firearms expert, I can confidently say that the Brownells BRN-15 stripped lower receiver is an excellent option for anyone looking to build their own AR-15. What sets the BRN-15 apart from its competitors is its exceptional quality for its price point.
After many hundred of AR builds, I find that Brownells constantly floats to the top of the list. You’ll be hard pressed to find anything near this quality for the price.
3 – Best Billet AR-15 Lower Receiver for the Money – Aero Precision M4E1
Probably the most recommended lower receiver for building your own rifle in the history of the AR-15. Aero Precision is known for its quality products, and every M4E1 made by Aero Precision is worth the time invested in finding one available. Some of the best machining you will see on a forged AR-15.
This AR-15 lower receiver comes with the following features:
- 45 or 90-degree selector switch
- Tension screw to keep your AR-15 upper and lower tight
- Soft curves of 7075-T6 aluminum for comfort
- Flared mag release opening for easier and faster one-shot magazine changes
- Hardcoat anodized finish to resist surface wear and tear in 2 color options
This billet lower receiver comes with an affordable price tag, easy parts compatibility, and the lightweight design of a forged receiver.
The M4E1 is made from 7075-T6 aluminum that is precision machined to final dimensions, making it compatible with all standard mil-spec AR-15 parts allowing you to make your ultimate rife.
Aesthetically, it has a nice and smooth design, making it look elegant and not chunky like many other AR-15 milled lower receivers. I know all you tough guys don’t care about how your rifle looks, but I find M4E1 just looks plain good when it’s built.
So, it is considered a lower receiver but actually comes with an integrated trigger guard, which makes the receiver a bit more rigid and stable in comparison to a standard lower. This, therefore, eliminates the risk of accidentally breaking off a trigger guard tab when you’re assembling or working on the rifle.
We’ll talk about the different sizes and styles of trigger guards below in more detail, but this specific model features an enlarged trigger guard opening so you can also easily handle the weapon when wearing gloves. I find it’s perfect for guys like me with bigger hands who struggle finding a comfortable grip on their ARs.
***Update***
The M4E1 is currently on sale through our certified supplier until December 16, 2024. Make sure to use the link below to pick one up at this all time low price.
4 – Best Polymer Lower – KE Arms Stripped Lower Receivers Polymer
This AR-15 stripped lower receiver is made from injection molded 30% glass-filled-nylon that includes the pistol grip, buffer tube, and trigger buttstock as well as the integrated trigger guard as components.
Thanks to this manufacturing process and lightweight material, this polymer lower receiver has several advantages over other AR-15 lowers:
- Lighter weight in comparison to other lower receivers with similar configuration
- Lower cost
- Increased production speed due to the integrated design so they can keep up with high demands in the market.
- Flared magwell for easy reloads
- Improved grip
This means this easy-to-carry, simple-to-assemble polymer lower receiver is almost never out of stock!
Additionally, it’s compatible with most other mil-spec parts and cassette-style match triggers.
Plus, it’s available in 2 finishes in either brown or black, and gets additional points for being easy to install, affordable, having durable hammer pins and an included safety selector hole.
***Update***
This lower is currently on sale through our certified supplier with the same deal mentioned above with the M4E1 until December 16, 2024.
5 – Best 9mm AR-15 Lower – Palmetto State Armory PX9
This complete AR lower receiver by PSA is ready to install with your 9mm upper. It is made from aircraft-grade aluminum and coated in an anodized finish for a sleek and professional look.
Because it is a complete lower, you don’t have to do any assembling yourself; it’s ready to be combined with your upper, so you can be off to the shooting range in no time!
In fact, this is a great option for someone just starting out or someone who wants to keep using their 9mm without getting a whole new gun. The lower is designed by PSA to specifically work with their hybrid 9mm uppers, which is a nice touch for loyal customers of the brand.
For something extra, PSA also throws in some special features like:
- PSA-enhanced polished trigger
- SBA3 stabilizing brace
- Accepts factory Glock magazines
***Update***
The PSA PX9 is currently on sale with the same offering as the Stealth mentioned above until December 13, 2024. They’re selling it at a 35% discount. This is an all time low folks, use our link before to ensure you’re getting the real product.
6 – Best 80% Lower – Type III Hard Anodized Billet AR-15 80% Lower Receiver
Now, this 80% lower receiver is manufactured using US-sourced aerospace grade 6061-T6 aluminum, which is very resistant and easy to mill. This means you will have a very durable lower receiver that is still easy enough for you to work with to bring it to 100% functionality.
Because 80% lower receivers are not considered a firearm by the ATF, you can get your 80% lower shipped right to your home without having to go through any FFL procedures.
This type of AR-15 lower receiver also means you can do a lot of customization on your own, which can be very satisfying and will effectively help you understand how your weapon works.
As this lower comes in mil-specs, it’s compatible with all other AR-15 parts so you can create your perfect gun in no time.
It features a broached, flared mag that makes fast reloads possible and a heavy-duty integrated trigger guard, making it suitable for outdoor or winter use even with gloves.
The forged 7075-T6 aluminum build and mil-spec design of the BRN-15 provide unmatched durability and reliability. Its precision machining allows for compatibility with a wide range of mil-spec AR-15 components, giving you the freedom to customize your build to your liking.
But don’t be fooled by its simplicity – the BRN-15 also boasts a matte black, Type III hardcoat anodized finish, giving it a sleek, military-like appearance. And with Brownells’ reputation for outstanding customer service and fast order turnaround times, you can rest assured that your experience with the company will be a pleasant one.
Moving on to the Type III Hard Anodized Billet AR-15 80% Lower Receiver, this option is not for the faint of heart. As an 80% lower, it requires a certain level of expertise and familiarity with the AR-15 platform to assemble. However, for those willing to put in the effort, the results can be incredibly rewarding.
Crafted from aerospace grade 6061-T6 aluminum, this 80% lower provides unmatched durability and resistance. And because it is not considered a firearm by the ATF, it can be shipped right to your doorstep without the need for FFL procedures.
But where the Type III Hard Anodized Billet AR-15 80% Lower Receiver truly shines is in its customizability. Its mil-spec design allows for compatibility with a wide range of AR-15 components, and its broached, flared magwell and heavy-duty integrated trigger guard make it suitable for use in any environment.
When it comes to recommendations, I would urge anyone interested in the Type III Hard Anodized Billet AR-15 80% Lower Receiver to do their research and fully understand the level of expertise required before attempting to assemble it. However, for those up to the challenge, the Type III Hard Anodized Billet AR-15 80% Lower Receiver offers unparalleled customizability and durability.
However, keep in mind that to assemble this kind of lower, you really need to know how the AR-15 works as it’s not exactly beginner-friendly. But once you get the hang of AR-15s and want to really customize your weapon, this is the 80% lower we’d go for.
7 – The AR-15 Lower to Avoid – Lead Star Arms
Lead Star Arms LSA-15 shows what a traditionalist can do with the AR-15 platform and a billet of aluminum. Lead Star uses trusses to reinforce the lower while keeping weight down, using a Magwell grip CNC’d into the lower Flared Magwell and a unique oversized trigger guard.
The reason why we cannot recommend this lower to everybody, however, is that this billet lower is amazing for AR builds only if paired with an LSA AR-15 upper. Unfortunately, the lower and mil-spec uppers don’t mix well because the lines aren’t matched up.
LSA wants you to buy an upper from them and while their uppers are great, it does narrow your options if you care about the lines matching on your upper and lower.
Also, it is definitely at the higher end of our price spectrum so we would not recommend it to someone who is looking for an affordable lower receiver to start their self-build AR-15 journey.
Not to mention…
The stripped lower is currently sold out, but you can get the complete receiver set, so you obtain a complete upper with take-down, bolt catch pin, and set screw. Which as I mentioned before is the path you’ll need to take with this one anyway…
The Top Brands for AR15 Lowers
Here we’ll present you with 8 of the best sellers and brands for your AR-15 lower receivers. Starting off with our favorite: the Palmetto State Armory, which offers a great selection of Lower Receivers and anything else you could want or need for your AR-15 build.
Palmetto State Armory
Palmetto State Armory grew out of 5 engineering and metal manufacturing companies with one aim in mind:
Put guns into Common Use. They strive to sell as many AR-15s and AK-47s as possible to protect the United States against further infringement on the Second Amendment.
To that end, they offer a 100% lifetime warranty on PSA firearms.
Thanks to their great customer service, low prices, and high customization, they are thought of as one of the best companies to buy any firearm, especially an AR-15.
Brownells
Brownells is an old school family business founded in 1938 and has been known for providing high-quality guns and gunsmith equipment ever since. The company stands for technology and research while still focusing on their customers to ensure everyone is well looked after.
Over 75 years and three generations, Brownells has grown into one of the biggest suppliers of firearms and accessories in the world, with a staggering supply of unique rifle choices that offers over 90,000 gun parts, tools, supplies and ammunition.
Anderson
Anderson Manufacturing lowers are made from the same billet 7075-T6 aluminum, and have about the same Type III Hard-Anodized Finish, usually at a lower cost than what other suppliers offer.
Now, Anderson lowers are every bit as durable as PSA or Aero Precision but they have a few more minor imperfections. A couple of burrs not hand ground, some rougher lines, and the ability to slice open your hand while changing a magazine are just a few reasons to spend more on your lower.
But if at the end of the day Anderson is all you can find or afford, there is nothing wrong with hand-finishing your lower to get rid of any rough edges.
F1 Firearms
This Texan Firearms Manufacturer focuses on AR components and complete firearms systems. They produce some of the best semi-automatic weapon systems on the market and combine high-quality materials with modern manufacturing equipment and in-house machining.
Essentially, they offer accurate and dependable products thanks to their quality control, and there’s even an option available for getting a custom-color coating for your pieces.
Aero Precision
Aero Precision started off as an aircraft parts manufacturer that turned to the production of military equipment in 1993. Aero Precision are some of the most sought-after lowers due to their quality and price.
Several companies contract out to Aero Precision for their lowers, and it may be worth looking into the different brands manufactured by Aero Precision if you’re picky about your badging.
They offer kits with specialized features to make home-building extra easy. Plus, you can get upgrades such as receiver tensioning screws or beveled magwells to make your rifle feel more high-end.
Battle Arms Development
This company is known for its high-quality and innovative designs with a focus on small arms design, including firearm components, tools, gauges, accessories, and complete weapon systems.
Battle Arms Development research and design their products very thoroughly, and thanks to unique and out-of-the-box thinking, they have been granted over 50 patents already since their creation in 2009. Not bad if you ask us!
Their products are 100% made in the US and held to the highest manufacturing standards, which you really notice when you use their gear!
Lewis Machine & Tool Company
LMT was founded in 1980 and has a long history of providing precision-engineered and high-quality weapons to the US military, government agencies, and law enforcement. They focus on weapon components and modular weapon systems, which they deliver at a high quality and a low price.
Their products are 100% made in the US and while they still serve the US military and law enforcement, they now also supply foreign military services as well as commercial retailers. This means their high-quality products are now also available for civil customers that can benefit from decades of experience by LMT.
American Defense Mfg (ADM)
ADM is a very high-end manufacturer that makes a premium line of specially designed lower receivers with an ambidextrous design. These lower receivers can perform any administrative operation quickly from either side, making them a popular choice for high-end and/or left-handed users.
Things to Consider When Buying an AR-15 Lower
When it comes to buying the AR-15 lower that works best for you, you need to first figure out what you want to use it for. If you want to use it for hunting, for instance, weight will be a big factor, whereas someone who wants to mainly use it in the shooting range will focus more on accuracy than some extra ounces of weight. (1)
This then determines what features you need, which ones would be nice to have, and how all of this fits into your budget.
Depending on your experience (and patience), you can also opt for a complete lower receiver that is ready to go, or you can build your own customized one by buying a stripped lower and/or an assembly kit.
We will go into the various options and tech specs when it comes to buying your lower receiver in more detail below. But first, we’ll go over what the lower receiver actually is and why it’s the heart and soul of your weapon.
How an AR-15 Is Built
An AR-15, broadly speaking, is made up of two elements:
- The upper receiver
- The lower receiver
So the construction is actually very simple and straightforward but can appear complicated due to its design.
Let’s look into these 2 components in more detail:
The Upper Receiver
The upper receiver houses the charging handle, bolt carrier group, and barrel. All the steps of firing a bullet (round) are contained within the upper and include:
- Feeding
- Chambering
- Locking
- Firing
- Unlocking
- Extracting
- Ejecting
- Cocking
The upper receivers are mostly made of forged 7075-T6 aluminum and the barrel is usually manufactured in standard sizes. This is where you add on accessories and extra gear like sights, optics, a muzzle, and so on, mostly through a rail system.
Other components of the upper are the gas block and tube, which funnel the burning gases, and the handguard, which protects the shooter’s hands from the heat.
The Lower Receiver
Now let’s get into the most interesting part of your AR-15 build: the lower receiver.
This part of the gun is its heart; without it, it cannot function, and it’s also why this is the part you need a serial number for!
But let’s start at the beginning.
The basic components of a lower receiver are:
- The fire control group (installed inside the lower and encompasses the trigger and hammer)
- The magazine well (a hole on the bottom side of the lower where the box of rounds, or the magazine, is inserted to feed the upper)
- The pistol grip (what is gripped by the shooter’s firing hand, allowing a person the ability to comfortably pull the trigger)
These elements are what make the weapon fire a bullet, therefore the only part of the AR-15 that is legally considered a firearm.
In addition to the aforementioned elements, you need additional parts to complete your lower receiver, which are:
- Trigger assembly
- Trigger guard
- Magazine catch/release
- Threaded bolt catch and release
- Safety selector switch
- Grip
- Takedown pins
- Receiver extension (buffer tube)
- Buffer and spring
- Buttstock
Now, this might look like a lot if you’ve never built an AR-15 but there’s no need to worry. Most manufacturers sell complete lower receiver kits where you get everything you need, so you don’t have to worry about missing an important piece halfway through your build.
The lower receiver is usually made from billet 7075-T6 aluminum and fulfills a variety of functions, like supplying the rounds to the upper and enabling the gun to fire a round via the trigger and hammer. The buttstock is the piece of the gun that you place against your shoulder that enables you to fire with accuracy and precision.
When you’re building your AR-15, you need to join the lower and upper receivers together. Once they are conjoined, they create a rifle that’s very easy to assemble and disassemble for cleaning and maintenance. This also comes in very handy if you want to swap between different calibers; just swap out the more universal lower for uppers with different calibers.
This design makes the AR-15 one of the most versatile and modular rifles on the market today and also why it’s such an easy gun to customize.
Like we said in the beginning, it has a very simple structure, making it a great gun for beginners.
This versatility means you can use it for a variety of different tasks such as home defense, range shooting, and also for hunting and other outdoor purposes.
Once you have the basic setup for your AR-15, the options to further customize it are almost limitless. You can get loads of extra accessories like sights, bipods, optics, forearm grips, and more, to create your perfect weapon.
Now let’s look into some more details about the manufacturing process, different materials, and the other tech specs of your AR-15.
Different Types of Lower Manufacturing
To put it simply, Cast, Billet, Forged, and Polymer are the manufacturing methods.
Cast lowers are made in a mold. Billet receivers are made by machining one piece of aluminum. Forged receivers are created by forging as much of the lower as possible before machining.
Polymer ones are the odd man out as the injection molded plastics differ by company.
Billet
In a few words, Billet lower receivers are for your more artistic builds and your smaller shops. They can innovate because they don’t require a complete change in the process, only a few lines of code.
But did you know that Billet lowers are the most expensive because the manufacturers take the metal to the limit of their imagination. Billet lowers are CNC’d out of one solid block of aluminum. Companies like Spikes Tactical took this to the extremes with several amazing lowers, but they are still novelty items compared to most standard ARs.
Billet lowers also have unique stress points and different aluminum, making them slightly less durable than forged ones. Due to the way they’re made, the grains of the metal get interrupted, resulting in a slightly lower tensile strength. But they are still safe to use for regular shooters that do not use their guns in extreme environments.
Also, because of the relative ease in changing the manufacturing process and design, these lowers can often be more innovative and changes are faster (and cheaper) to implement from the manufacturer.
Forged
So, Forged Lowers are usually made from 7075-T6 Aluminum and are a massive improvement over cast, and some consider over billet as well (Mil-Spec for AR lowers is forged aluminum).
The process starts by heating two blocks of aluminum to about 1/3 the melting point and then smashing them into shape with a massive hammer. Followed by CNC-ing the lower to clean it up, and you have a forged lower.
The forging process changes the grain flow of the metal and creates an amazingly strong, yet low cost (after the initial investment), lower.
Most big manufacturers use forged lowers in their AR-15s, and most lowers available are indeed forged. In fact, the classic lines of the M16 and M4 are there because the US Military requires forged lowers.
Because of the more complex manufacturing process, changes are harder to implement and therefore the designs are often a bit less innovative and more standard.
Cast
Cast lowers are the cheapest but they have a lower shear strength when compared to the forged or billet lowers.
The other processes have also become cheap enough that they’re hard to find nowadays, but many DIY builders will cast their own lowers.
80% Lower Receiver
An 80% lower receiver does not convey its manufacturing technique, but more the degree of completeness of this manufacturing process.
These requires the most effort on your part, as you need to do quite a bit of work on it to transform it into a 100% working lower as it won’t be able to fire without some milling.
You need to:
- Machine out the trigger pocket
- Finish the holes for the safety selector and trigger
- And some more steps
This can take an experienced builder 2-3 hours and can take even longer if you’re a beginner. So we actually would not recommend a beginner to start here!
Because it’s not functional as a firearm when you buy it, an 80% lower is not officially considered a firearm by the ATF, so you can still buy it without the FFL process and get it delivered straight to your home (confirmed at the time of writing).
It also does not have a serial number.
Beavertail
The beavertail is a cut that changes from the forged receiver to the CNC’d lower. A smooth transition with no solid edge is what you’re looking for, with no burr marks or edges from the machining process, creating a smooth fit for the fleshy part of your hand.
Materials Used in Lowers
Polymer lower
These receivers are generally not the first thought of most AR builders. But with improvements in polymers and the success of Glock, it wasn’t long before the AR market found polymers to have benefits for rifle builds, most notably to the weight.
Polymer AR-15 lower receivers are made in much the same way as forged and billet lowers – getting a rough shape and then machining it to complete its detailed shape.
But the material is much easier to work with than aluminum.
Polymer lowers are not new but they’ve been gaining popularity in recent years. However, they won’t stand up to punishment like a forged or billet lower, which are considerably more durable.
Aluminum
Most AR-15 lowers are still made from aluminum these days, and there are 2 main types of aluminum used:
- 6061-T6 aluminum
- 7075-T6 aluminum
While the 7075-T6 aluminum is stronger, it costs more and is harder to work with because of its stability.
60661-T6 aluminum is cheaper and also easier to work with, making the manufacturing process faster and cheaper at the expense of durability for the end user. But 6061-T6 is still a safe and suitable material for someone who’s planning to use their gun for hunting, self-defense, or range shooting.
Only if you’re planning to use your gun in very extreme circumstances should you insist on utilizing 7075-T6 aluminum.
Different Types of Triggers
If you weren’t aware, there are actually a couple of different sizes for the trigger, each having its own benefits and drawbacks:
Trigger Guard Oversized vs Standard
Oversized trigger guards are becoming the new rage.
So, originally made for shooting with gloves, an oversized trigger guard allows for more freedom of movement. The largest draw is getting the trigger guard to precisely fit your hand with the equipment you want to use. A standard trigger can be made to have more depth but not more length.
Standard trigger guards, like all standard features, have nearly 60 years of aftermarket support. If you purchase a lower with a standard trigger guard, you can usually switch it to a nearly oversized one by swapping a part and changing a few pins.
Finishes
Now, the finish of your AR-15 determines how your weapon will look in the end and what kind of aesthetic you want to go for.
Most manufacturers will ship their parts with a black hard anodized finish that is sleek-looking and simple. You can sometimes also get an unfinished or “raw” lower, but that’s often just the case for 80% lowers when you still need to do additional work.
Another option is to get a Cerakote finish, which is a proprietary ceramic finish that can be applied in loads of different colors and designs, the most popular being camouflage designs. Keep in mind that such special finishes often cost a bit extra.
Magwell Flared or Square
Flared magazines are just that: a wider opening to reload your magazine.
Simply put, a flared magazine forces the magazine to slide in faster, making it easier to change your mag and allowing for more rounds in a shorter amount of time.
Fitment
No one likes slop in their equipment. How nicely, beautifully, or tightly parts fit together is one of the two major indications of quality.
When building an AR-15, this is no different, but because of the nearly infinite amount of lower manufacturers and upper receivers to bolt together, some will be slightly out of spec by a few millimeters. This can impact the fitment of the different pieces and the overall stability and appearance of your finished gun.
Ambidextrous
Ambidextrous lowers allow you to quickly manipulate your rifle with either hand. This is a great feature for switching between hands or left-handed shooters.
Protip: Left-handed shooters should not only look at ambidextrous lowers but also left-handed uppers. This way, they can make sure to avoid getting hit in the face by flying brass, and will also be able to shoot better with a rifle built for their specific needs.
But both right-handed and left-handed shooters can benefit from the ease of magazine changes and charging the rifle with an ambidextrous design.
The downside is that the rifle becomes more complex. Ambidextrous lowers fail the K.I.S.S test (keep it simple stupid). And here’s why:
The addition of the ambi safety, magazine catch and threaded bolt catch add weight and take up space in your lower. They get caught on bush, clothing, or sometimes they can be mishandled.
Frankly, a standard lower can be used with either hand if you practice with it enough. Practice beats price every day of the week, and because the rifle has less parts, they work better and last longer. You just have to decide if it’s worth the tradeoff.
Skelontonized AR-15 Lower
Skeletal lowers are usually billet lowers made to reduce as much weight as possible, often around the magazine. Skeletonizing is done to reduce weight at the expense of dirt entering the mechanisms.
Yes, they are cool, but like most novelty guns, you have to decide if you can afford the novelty. Allowing dirt, mud, or debris to enter the AR lower will just cause trouble down the line. But the weight reduction can be huge, with some lowers weighting as little as 6 oz.
Stealth
Stealth Lower is a term for not having a massive ugly manufacturer’s marking or emblem on the lower. However, some lowers like Colt, BCM, Noveske are prized and increases the value of the AR.
Many companies are better served with stealth lowers to hide the indication of an AR build. Stealth Builds are usually within $5 of a marked lower and have no differences besides containing as little selector markings as possible. A keen eye will be able to read the company’s name but most people won’t bother.
The other benefit of the Stealth lower is that you can have a custom laser engraving to personalize your lower without any of the intrusive emblems getting in the way.
Side Folding
Side folding ARs is a novelty that allows the AR-15 to use a folding buttstock through the use of capturing the recoil spring. They are great for building a small profile firearm or for reducing the size of a long rifle into an easier-to-manage system. They only reduce the overall length by citation needed but they’re well worth it.
The trade off is that they don’t have the structural security of a dedicated buttstock. It can seem firm and will probably even support weight if tested, but it will not be as strong as a rifle without the fold.
Match Upper and Lower
The matching surfaces of the lower and upper receiver don’t change the accuracy of the AR-15. But no one likes a loose gun; it feels inferior, similar to the case of fitment we mentioned above.
A matched lower and upper receiver will have a tight fit, whereas with mismatched uppers and lowers, there is always a risk of there being gaps of a few millimeters.
You see, a matched set is designed and engineered together, and the upper and lower will have a matching finish. This way, the rifle will look more like a completed firearm instead of a build unit.
The differences in AR-15 lower receivers come down to quality and features.
A high quality lower is built differently, takes more punishment, has a more pleasing finish and is just better machined. The most noticeable differences are the weight and machining of the functional features.
The weight of a high-end lower will be slightly lighter because more material has been removed during the machining process, but the lower will feel nicer and more pleasing. The fitted nature comes from the machining, which is done more precisely, in several rounds and with better equipment.
But most low-end lowers are machined in one pass of a CNC machine, leaving burrs and hand cutting angles. Mid-Tier ones will be finished in two passes, smoothing the curves and removing the ridges, while high-end will be almost molded to your hand.
And so, like we’ve mentioned, the question is how much you are willing to spend to get a more high-end product.
Billet AR-15 Lower vs Forged Lower: Which is Better?
As we’ve seen above, forged or billet aluminum lower receivers each have their advantages and disadvantages. The answer to the question, “is a billet or forged lower receiver better,” depends on your budget and how you’re planning to use the gun.
A forged lower is usually more durable and stable, but the designs are a bit more traditional and harder to change. A billet lower receiver can be more customizable and have more special features, but they are slightly less robust and are also often more expensive than a forged lower receiver.
What Is a Stripped Lower Receiver?
Lower receivers are a lowers that come without any of the pieces that make it work, while a complete lower is already decked out and ready to go.
We recommend a stripped lower because you can customize your gun more easily and in case anything goes wrong, you know exactly how it was put together so you can identify the error faster.
The stripped lower is a completely machined lower, but does have the essential parts to function like a trigger, springs and pins. It is nonetheless already considered a firearm, and has to be bought through a licensed dealer (FFL) including the background check.
However, because there is more demand for a stripped lower than for an 80% lower, they are often cheaper to find.
You will need about 30 extra parts and some specialized tools like an armorer’s wrench to complete your stripped lower but what’s great is you’ll learn a lot in the process and will be able to really put your personal mark onto the weapon while you assemble it.
What Is a Complete Lower?
A complete lower receiver is a lower which comes with the majority of the parts for it to be used.
Everyone that builds an AR knows just how annoying it is to be done with your build only to shoot a detent spring across the room and need to wait for shipping to fire your rifle. Complete lowers are ready to go as soon as you get them and you won’t have to worry about anything breaking or going missing while you assemble it.
The only thing you need to do when you get your complete piece is to open the takedown and pivot pins, position your upper and capture it with the pivot front pin. Then you rotate the upper into position and secure it with the takedown pin.
That’s it, you’re ready for the shooting range.
Stripped vs Completed – Which is Right For You?
We would still recommend a stripped lower for your first rifle, because that way you get the opportuninty to learn what you’re able to do with your gun and just how easy it is to build or repair.
Which level of completion works best for your lower also depends on your budget and how much work you’re willing to put into the assembling process.
Buying a kit can be a good compromise because while you will have to assemble the parts to complete your stripped lower, you can be sure you will have everything you need in the kit and won’t have to worry about if you’ve forgotten to order an important piece of gear.
Where to Buy an AR-15 Lower Receiver
The AR-15 is a very popular weapon for gun enthusiasts because the possibilities of customizing are almost limitless. But there are some things to keep in mind when buying your lower receiver.
The lower receiver of your AR-15 is the part of the gun that is considered the actual firearm, so it needs to be serialized. The process of buying it can vary across the different states in the US and can take a few minutes, or a couple of months. Here’s a map that gives a broad look of the different requirements for each state.
Every stripped lower is issued a serial number and is regulated by the ATF. You need to go through a background check to be able to purchase it. The NICS electronic background check is run by the ATF.
You also need to purchase the stripped lower through a FFL (Federal Firearms Licensee), which will run the NICS. You can’t just have the lower delivered to your home but will need to pick it up at the FFL, where they run the NICS, and once it comes back clear, you’re good to go.
(Exceptions are the 80% lower receivers, like we’ve described above).
However, you can get all the other parts of the lower receiver at a variety of suppliers, without having to go through the background check. Only the stripped receiver has the serial number and requires the NICS. (2)
What Calibers Can Be Used in AR15 Lower
This is a pretty involved question, for that reason we wrote a whole article on what calibers can be used in an AR-15 lower receiver. We cover all you need to know to make sure you’re getting the right lower.
Frequently Asked Questions
How Much Does an AR-15 Lower Receiver Cost?
How much an AR-15 lower receiver costs depends a lot on what type of lower receiver you want to buy. Most cost around $100 USD.
What Should I Look For in an AR Lower Receiver?
When it comes to buying your AR-15 lower receiver, you should look for a good quality product that really meets your personal needs such as: What will you use your AR-15 for? What’s your budget and are you willing to push it for better quality? Do you want to get a complete lower or assemble it yourself?
What Is the Best 80% AR-15 Lower Receiver?
We recommend the Type III Hard Anodized Billet AR-15 by 80% Arms as the best 80% receiver purchase because of its high-quality manufacturing and durability. It comes with mil specs and is made from durable but easy to work with 6061-T6 aluminum, and is compatible with all other AR-15 parts.
Which AR-15 Inexpensive Complete Lower Has the Best Trigger?
The inexpensive AR-15 complete lower with the best trigger is the AR-15 Freedom Classic Lower. It’s a great complete lower with a solid and sensitive trigger.
What Lower Receiver Does the Military Use?
The military currently uses two lower receivers, the XM5 rifle and the XM250 automatic rifle. For soldiers involved in close-quarters combat, the XM5 will eventually replace the M4/M4A1 carbine rifle, while the XM250 will replace the M249 Squad Automatic Weapon.
Are Anderson Lowers Good Quality?
Anderson Lowers are known for being good quality products at a low price point. While they might have some minor imperfections in comparison to more high-end products, they’re still durable and safe options to purchase.
Further Reading
Best AR-15 Furniture Accessories for 2023
Trying to deck out our rifle, then take a look at the best AR-15 furniture accessories for 2023.
Most Reliable AR-15 Rifles
Interested in picking up a complete AR? Then we’d such taking at look at our article on the most reliable AR-15 rifles.
Our Recommendation – PSA AR-15 “Stealth” Stripped Lower Receiver
References
- Jordan Sillars, Should Your Next Deer Rifle Be An AR-15, retrieved from https://www.themeateater.com/hunt/firearm-hunting/shoud-your-next-deer-rifle-be-an-ar-15
- Greg Myre, A Brief History of The AR-15, retrieved from https://www.npr.org/2018/02/28/588861820/a-brief-history-of-the-ar-15
Andrew Maurer is a Precision Rifle Series competition shooter and gunsmith and has been building competition rifles for over 12 years. He works as a big game hunting guide in Iowa, South Dakota, and Arizona. He is also a political scientist studying the effects of gun control on society. He teaches youth rifle shooting.
📧 Reach me via email at: Andrew@riflegearlab.com