The lower receiver makes up nearly half of an AR-15. But it often gets brushed over as the best place to save money on an AR-15 build.
While the lower receiver has fewer moving parts and is less prone to causing reliability issues than the upper receiver, using the cheapest lower receiver you can find is usually a bad idea.
The two main things that you want from your lower receiver are a good fit and finish. Almost all the ergonomics of your rifle are from the lower receiver, and the connection between your upper receiver and lower receiver needs to be clean and tight in order for your rifle to function properly.
So you want a lower receiver that’s built to exacting standards. Fortunately, you don’t have to spend a whole lot to get a well-fitting lower receiver.
Our Best Choice
Spoiler: If you need a solid lower receiver right now, pick up the Aero Precision AR-15 Gen 2 Lower receiver. Aero Precision lowers are easily the best all-around lower receivers on the market, when price, features, and quality are figured into the equation.
The Top AR-15 Lower Receiver You Can Buy
Top 7 Best AR-15 Lower Receivers (Updated 2021)
Here are the top performers, sorted from lowest to highest priced.
Aero Precision AR-15 Gen 2 Stripped - Best Overall AR-15 Lower Receiver
- Anderson Manufacturing Stripped - Top Budget Lower
- James Madison Tactical 80% Polymer Gen 2 - Best Polymer
- Spikes Tactical Mil-Spec - Best Full-Auto
- Seekins Precision SP223 - Best Ambidextrous
- Battle Arms Development BAD556-LW - Best Lightweight
- Radian Weapons Ambidextrous Lower Receiver - Most Complete
1. Aero Precision AR-15 Gen 2 Stripped Lower Receiver: Best Overall AR-15 Lower Receiver
The Aero Precision AR-15 Gen 2 Lower Receiver is the no-frills workhorse of the lower receiver market.
Aero Precision builds all their lower receivers from forged, 7075-T6 aluminum. The Gen 2 is strong enough to be the base for 5.56mm, 6.5mm, 6.5mm, 300 Blackout, and 9mm AR-15s.
The Gen 2 is built with a mil-spec form factor. So the look and function is very basic, and there’s no integrated trigger guard.
There’s a receiver tension adjustment screw at the rear of the Gen 2 that adjusts how snugly this unit marries to your upper receiver. This enables you to tighten the fit so your rifle rattles less and has more precise tolerances in the action.
So, although the Gen 2 offers little in the way of aesthetics or added ergonomics, it’s an incredibly well built piece that delivers outstanding performance in any context.
2. Anderson Manufacturing AR-15 Stripped Lower Receiver: Best Budget AR-15 Lower Receiver
The Anderson Manufacturing AR-15 Lower Receiver is the Honda of AR-15 lowers. It’s inexpensive, but will last for the rest of your life.
This lower receiver is built from forged, 7075-T6 aluminum. The aluminum is coated in mil-spec hard-coat anodizing, for excellent corrosion resistance.
There’s no integrated trigger guard, and the form factor is standard mil-spec.
Although there’s no tension adjustment to tighten the connection with the upper receiver, the standards are exact, and there’s very little rattle when the rifle is completely assembled.
The Anderson Manufacturing Lower Receiver is definitely the best choice for any AR-15 builder who wants a solid platform to build their rifle on, while conserving the majority of their budget for other parts.
3. James Madison Tactical AR-15 80% Polymer Gen2 Lower Receiver: Best Polymer
Polymer is a fairly new addition to the AR-15 lower receiver market. However, it’s strong and durable enough for most applications. The James Madison Tactical AR-15 80% Gen 2 Lower Receiver sets the standard for polymer AR-15 lower receivers.
The most notable thing about this lower is that it’s only 80% complete. An 80% polymer lower is much easier to complete than an 80% aluminum lower because polymer is easy to machine and drill.
James Madison Tactical includes a jig and instructions for drilling and machining the 80% part into a complete lower receiver. However, you’ll still need the drilling and machining tools to finish this piece.
To ensure durability, this lower is reinforced along the magazine well, at the bolt release posts, and at the upper receiver interface points for more rigidity and a better upper receiver fit.
For added ergonomics, the integrated trigger guard is rounded for better trigger access with gloves on, and the front of the magazine well has serrations for your support hand.
Overall, the 80% Gen 2 is an excellent option for those who want a lightweight lower receiver, and don’t mind doing a little machine work to complete their rifle along with a dependable magazine.
4. Spikes Tactical AR-15 Mil-Spec Lower Receiver: Full-Auto
The Spikes Tactical AR-15 Lower Receiver is not full-auto from the factory. However, it’s the best option for those with the capability to legally convert an AR-15 to full auto.
First, the Spikes Tactical lower is a standard mil-spec form factor. This means that there’s no integrated trigger guard, and the upper receiver fit is established with just the takedown pins. However, the fit and finish is outstanding and there’s very little rattle from a completed rifle using this lower.
However, the ruggedized, hard coat anodized finish is thicker and more durable than a mil-spec finish. It also has a more matte appearance.
Spikes Tactical includes a full-auto selector icon. However, you’ll still need a full auto trigger group, a drill press, and a federal firearms license (FFL) to make this lower full-auto. Remember, converting a firearm to full-auto without an FFL is a federal offense.
This unit is forged, 7075-T6 aluminum, so if you use it in a full-auto build, it will hold up to the abuse.
In the end, this receiver is most ideal for people who can legally convert a rifle to full-auto or those who want the novelty of the full-auto selector icon, since there are equally high quality lower receivers available for less.
5. Seekins Precision SP223 Billet: Best Ambidextrous AR-15 Lower Receiver
The Seekins Precision SP223 Billet Lower Receiver is designed for ambidextrous controls. But it comes with a slew of other features.
First, the SP223 includes a left-handed bolt release. You’ll still need to install a standard bolt release and an ambidextrous fire selector switch for full functionality. But the Seekins ambidextrous bolt release is one of the least bulky and gimmicky ambidextrous options available.
The integral trigger guard is oversized for easier trigger access while wearing gloves.
Up front, the magazine well is flared for faster reloads, and the front of the lower is curved and serrated for a high-and-close CQB support hand position.
For fit, the SP223 has an upper receiver tensioning screw to remove upper receiver rattle, and there’s an included trigger reset screw for a tight trigger group fit.
Seekins also replaced all the roll pins with screw-in dowel pins for enhanced durability and reliability.
The finish is thicker and more matte than many mil-spec coatings. However, the coating does not exceed mil-spec standards.
Lastly, this receiver is milled from 7075-T6 billet aluminum. And there are cutouts milled into the magwell to reduce weight.
The SP223 is a bit on the pricey side. However, it’s an excellent option for left-handed shooters and anyone who wants a lower receiver with more ergonomics than a standard mil-spec piece.
6. Battle Arms Development BAD556-LW: Lightweight AR-15 Lower Receiver
The Battle Arms Development BAD556-LW Lightweight Lower Receiver reduces weight without sacrificing performance, which is tough to do.
The BAD556-LW is machined from 7075-T6 billet aluminum. Not quite as strong as forged aluminum, but still durable enough to work with almost any AR-15 caliber.
Where the BAD556-LW stands out is in the weight. This unit comes in at 6.84 ounces. It’s one of the lightest lower receivers on the market.
There’s also a flared magazine well for faster reloads and a relief cut for an ambidextrous fire selector switch.
The integrated trigger guard is rounded to accommodate shooting with gloves. And Battle Arms Development removes all the sharp edges by hand, for added comfort with the gloves off.
To make assembly easier, the bolt catch pin is a roll pin and the rear takedown pin detent spring is captured.
Lastly, the finish is hard coat anodized and thicker than mil-spec.
This is an excellent lower receiver for anyone doing a lightweight build or tactical shooters and competitors who want a lightweight rig for extended shooting sessions.
7. Radian Weapons Ambidextrous AR-15 Lower Receiver: Most Complete AR-15 Lower Receiver
The Radian Weapons AR-15 Ambidextrous Lower Receiver is not only completely ambidextrous, it also includes most of the AR-15 controls.
Radian Weapons milled this receiver from 7075-T6 aluminum, and milled weight-reduction cutouts into the magazine well.
While this lower isn’t ready to fire, it includes a magazine release button, bolt release, and fire selector switch. All of these controls are completely ambidextrous.
Additionally, this unit enables right handed shooters to lock the bolt to the rear without taking their firing hand off the weapon.
To strengthen the already outstanding ergonomics, the magazine well is flared for quick reloads, and the front of the receiver is serrated for a CQB support hand hold. The integrated trigger guard is rounded for easier trigger access, as well.
For fit, there’s a self-adjusting receiver tensioner that uses a spring pin to automatically adjust the upper receiver tension for an exact upper receiver fit without turning any screws.
The finish is mil-spec hard coat anodization, which is good, but a tad thin for a receiver at this price.
In the end, this model is an outstanding option for those who want a truly ambidextrous lower receiver without purchasing any additional hardware.
How to Choose a Lower Receiver
There are four types of lower receivers:
- Cast aluminum
- Billet aluminum
- Forged aluminum
Cast aluminum is the weakest. Forged aluminum is the strongest. And billet aluminum falls somewhere in between.
The main benefit of polymer is that it’s light and easy to drill.
Then, there are two types of aluminum:
6061-T6 is the weaker of the two. The only benefit of 6061-T6 aluminum is that it’s more corrosion resistant than 7075-T6. However, if you get a lower receiver with a good coating, corrosion won’t be a problem.
The cost of aluminum and manufacturing has come down enough that you shouldn’t need to consider using a cast lower or anything made with 6061-T6 aluminum, even on a minimal budget.
So, there are plenty of reasons to pay more for your lower receiver, but materials and construction aren’t good reasons.
Some reasons you should pay a premium for your lower receiver is if you want added ergonomic features, ambidextrous compatibility, or an extra lightweight piece.
To help you sort through the options—and there’s a lot—we’ve checked out all the best AR-15 lower receivers for you.
Now, let’s dig into some lower receiver reviews.
The lower receiver you choose will be determined mostly by your specific shooting context and personal shooting needs.
Even though there are some features that make things easier for certain shooters (like lefties), anyone can perform well with a standard mil-spec design and a little training.
That’s why the Aero Precision AR-15 Gen 2 Lower receiver is the best buy for just about everyone.
It’s a high quality lower receiver that will leave plenty of budget for getting what you need out of your furniture and upper receiver.
So, if you’re getting excited about your upcoming AR-15 build, grab yourself a lower receiver and get started on your dream gun that goes great with a well-built grip.