The AR-15 is America’s most popular centerfire rifle, and it’s easy to understand why. A quick glance at any firearms website shows dozens, or even hundreds of different modifications for the AR, so you can build a fully personalized rifle without breaking the bank.
But if you’re going to work with such a versatile platform, why not build your own AR-15 kit from the ground up? We’re about to look at the best AR build kits on the market. In this guide, we’ll look at a wide variety of kits, from 80% lowers to uppers to complete AR-15 receiver build kits.
In making our selections, we considered the overall quality of the components, including the trigger, the bolt, the chamber, and any accessories or extra features that may be included. We’ll also look at value, so expect to see a few cheap AR-15 build kits for the more budget-conscious hobbyist.
Best AR Build Kits
The Brownells AR-15 Tactical Receivers is a complete kit for building upper and lower receivers and attaching a buttstock.
Key Features
- Aero Precision Stripped Upper Receiver
- DPMS Forward Assist Assembly
- DPMS Ejection Port Cover Assembly
- Anderson 80% Lower Receiver
- DPMS Lower Parts Kit
- Black nylon buttstock
The Brownells AR-15 Tactical Receivers Build Kit is a custom AR build kit, developed by Brownells from a variety of other manufacturer’s parts. It’s their version of a high-quality, medium-cost AR build, and it’s remarkably complete. All you need to buy are a barrel, magazines, a pistol grip, and a jig.
Why a jig, you ask?
Like many lower receivers, the Anderson is an 80%, which means it needs to be drilled and tapped in order to be used in a functioning rifle. Even if you have steady hands and years of shop experience, you’ll need a jig to make sure your holes are precisely placed.
The Aero Precision Stripped Upper Receiver is one of the most reliable on the market, and features a Picatinny rail for accessories. All of the DPMS parts are well-engineered, particularly the lower parts kit, which actually has its own separate entry on our list.
Pros
- Custom Brownells kit
- Almost a complete rifle
- Quality DPMS lower parts
Cons
- Does not include jig for lower receiver
If you want to assemble every bit of your AR from the ground up, this receivers kit is a good choice.
2. Premium Receivers Build Kit
The Brownells AR-15 Premium Receivers is another complete kit, and requires only a rifle and a buttstock for completion.
Key Features
- Aero Precision Stripped Upper Receiver
- High Standard Forward Assist Assembly
- High Standard Ejection Port Cover Assembly
- Anderson 80% Lower Receiver
- Bushmaster Lower Parts Kit
- Black high-impact polymer pistol grip
The Brownells AR-15 Premium Receivers Build Kit is the second — and last — complete Brownells custom kit on our list. It shares a lot in common with the Tactical version, including the Aero Precision Stripped Upper Receiver with a Picatinny rail.
The High Standard upper receiver parts aren’t quite as well-machined as the DPMS parts on the Tactical kit, but they’re still serviceable — there just isn’t that much advantage to a high-end ejection port cover. And we’re just fine with the slight downgrade, considering the lower price tag.
The Bushmaster Lower Parts Kit pulls a tad heavier than mil-spec, and includes everything you need to get the 80% lower working, with the exception of a jig. Once again, you’ll need to provide that on your own.
Pros
- Custom Brownells kit
- Almost a complete rifle
- Inexpensive
Cons
- Does not include jig for lower receiver
This receivers kit is a great budget build that provides all the fun of assembling a complete rifle.
3. Premium Upper Assembly
The Brownells AR-15 Premium Upper Assembly is a simple kit for building a complete AR-15 upper receiver.
Key Features
- Aero Precision Stripped Upper Receiver
- High Standard Forward Assist Assembly
- High Standard Ejection Port Cover Assembly
The Brownells AR-15 Premium Upper Assembly Build Kit is a barebones choice, but we included it because a lot of people are happy with their existing lower and barrel, and just want an upper that isn’t as banged up. If that sounds like you, consider giving this kit a try.
The Aero Precision Stripped Upper Receiver forms the basis of the Premium kit, just as it does for both of Brownells’ complete kits. But we can’t stress enough just how well-machined this receiver is. The aluminum is precisely cut to mount on any mil-spec lower, and your barrel will attach with ease.
All of this comes at a low price, considerably less than you’d pay for a complete kit, or for an upper with a barrel.
Pros
- Reliable, mil-spec design
- Easy to assemble
- Inexpensive
Cons
- Not a complete kit
If you’re looking for a new mil-spec upper for your existing lower, this is a reliable, affordable upper assembly kit.
4. Upper Receiver Assembly
The Brownells BRN-180 AR-15 has a full-length Picatinny handguard,
Key Features
- Aircraft-grade aluminum receiver & handguard
- 16″ matte black barrel with flash suppressor
- Chambered in .223 Wylde
- Full-length Picatinny top rail with M-Lok rails at 1 3, 6, and 9, and 11 o’clock
- Molded polymer ejection port cover
The Brownells BRN-180 AR-15 Complete Upper Receiver Assembly is designed with target shooters in mind. The receiver and handguard are both precision machined from aircraft-grade aluminum, which is both lightweight and rugged.
And target shooters will appreciate the .223 Wylde chamber. This chamber is designed to safely, reliably fire both .223 Remington and 5.56mm NATO rounds. The rail system allows for a large number of accessories.
While the full-length top rail is nice, we like the 1 and 11 o’clock rails even more, since this allows you to install offset sights for shooting at different ranges.
This assembly kit is pricey, and you’ll still need to buy a lower receiver, pistol grip, and buttstock. But it’s a great upper assembly for anyone who’s serious about accuracy.
Pros
- Versatile, reliable chamber
- Plenty of room for accessories
- Good choice for target shooters
- High-grade aluminum construction
Cons
- Expensive
The .223 Wylde chamber is ideal for building a target rifle.
5. Billet Rifle Lower Receiver
The Foxtrot Mike is designed for 9mm cartridges, for lower recoil and better control.
Key Features
- Aircraft-grade aluminum billeted frame
- Designed for 9mm cartridges
- Mil-spec trigger
The Foxtrot Mike AR-15 FM9 Complete Billet Rifle Lower Receiver is a fully-assembled lower receiver, designed to feed 9mm cartridges. The 9mm’s lighter recoil makes this an excellent choice for a home defense gun, and you’ll also save money by purchasing cheaper pistol ammunition.
If you’re considering a 9mm AR, keep in mind that there’s a limited variety of barrels and upper receivers available in this chambering. But this lower is a good start to your build. It’s CNC-machined from a solid aluminum block, so it’s rugged enough to take a beating.
Because this is a complete lower, you’ll need to have it shipped to a licensed FFL dealer, not directly to your door. It’s still a great value, provided you’re only interested in home defense.
Pros
- Durable construction
- Low recoil
- Great for home defense
- Great value for the price
Cons
- Must be shipped to an FFL dealer
- Unusual cartridge size
This is a good choice if you plan on using your AR-15 primarily for home defense.
6. Lower Receiver Kit
The Brownells AR-15/M16 Lower Receiver Kit includes a well-engineered DPMS lower parts kit.
Key Features
- Anderson Manufacturing 80% Lower Receiver
- DPMS AR-15 Lower Parts Kit
- Black nylon buttstock
The Brownells AR-15/M16 Lower Receiver Kit isn’t a complete kit, just a lower receiver, but it’s a good choice to go with any .223 or 5.56mm upper receiver you want to use.
The main advantage of this kit is the Anderson Manufacturing 80% lower, which is the same one that’s used on Brownells’ premium complete AR kits. It’s forged from anodized aircraft grade aluminum, which makes it more durable than most 80% AR lowers on the market.
On the downside, there’s no jig included with this kit, so you’ll need to buy one separately or build your own.
The AR-15/M16 Lower Receiver Kit also includes the DPMS AR-15 Lower Parts Kit, which is one of the most well-machined mil-spec parts kits available. A black nylon buttstock completes the package. Choose an upper, a barrel, and a pistol grip, and you’re ready to hit the range.
Pros
- Durable aluminum construction
- High-quality parts kit
Cons
- Jig not included
This is one of the most rugged 80% lowers on the market.
7. 80% Lower Build Kit With Buttstock
The Brownells AR-15 80% Lower Build Kit With Buttstock features a polymer receiver that’s easy to machine.
Key Features
- Polymer80 80% Lower Receiver and Jig
- DPMS AR-15 Lower Parts Kit
- Brownells M4 Stock Assembly
The Brownells AR-15 80% Lower Build Kit With Buttstock is a complete AR-15 lower kit, including an adjustable buttstock, so you can shorten your rifle for use in tactical situations like home defense.
The lower receiver body is a Polymer80 brand, and includes their jig to guide in all drilling and tapping. Polymer drills more easily than aluminum, but be careful; it’s also easier to drill too deeply. Take your time, and you’ll have yourself a fine lower receiver.
The DPMS Lower Parts Kit makes an appearance yet again, and that should come as no surprise. It’s simply the best parts kit you’ll find anywhere near this price range. Speaking of price, this is an expensive kit. But considering the overall quality, it’s worth the investment.
Pros
- Easy to machine
- High-quality parts kit
- Adjustable buttstock
Cons
- Pricey
The adjustable buttstock in this lower assembly kit is perfect for AR-15 owners who want to use the same gun for home defense and longer-range shooting.
8. DPMS Lower Parts Kit
The DPMS AR-15 Lower includes a sturdy nylon buttstock and pistol grip that offer plenty of recoil absorption.
Key Features
- Complete mil-spec AR-15 lower parts kit
- Spare takedown detent
- Nylon buttstock and pistol grip
The DPMS AR-15 Lower Parts Kit is a mil-spec parts kit that includes a trigger spring, bolt catch, bolt catch roll pin, selector, selector detent, rear takedown pin, hammer, trigger, and 17 other pins, springs, and small components.
It also includes 2 sets of takedown detents and springs, so you can afford to lose one during assembly. Since this is a common beginner mistake, the extra detent and spring should be especially appealing if you’re rebuilding your fist AR lower.
The trigger has a clean break, without any creep, so you won’t inadvertently tense up when the gun is about to fire. That said, this is still a heavy, mil-spec trigger. Competitive shooters will prefer something with a little less trigger weight.
Pros
- Clean trigger break
- Sturdy buttstock
- Forgiving for beginners
Cons
- Not designed for target shooting
This lower assembly kit is a significant upgrade over just about any mil-spec parts kit.
9. BCM Lower Parts Kit
The Bravo Company BCM Gunfighter Enhanced Lower includes BCM’s unique pistol grip, which features an internal storage compartment.
Key Features
- Complete mil-spec AR-15 lower parts kit
- Includes BCM pistol grip
The Bravo Company BCM Gunfighter Enhanced Lower Parts Kit is a complete kit, including the trigger, hammer, selector, and all the pins, springs, and other miscellaneous parts.
It also comes with a BCM pistol grip. These grips have a hidden compartment can be used to store small accessories, or fitted with a specialized waterproof cutout for batteries.
The trigger in this kit features a crisp, clean break that won’t creep on you before it goes bang. It’s set slightly lighter than mil-spec, but still not as light as target shooters would prefer.
The internal components are manufactured from high-grade, corrosion-resistant steel that’s well suited for extended storage or long weekends hunting in foul weather. Beginners beware, though: there’s no extra takedown detent. If you lose it, you’ll have to order a new one to complete the assembly.
Pros
- Clean trigger break
- Rugged, corrosion-resistant construction
- Storage well inside pistol grip
Cons
- Poor choice for beginners
- Not designed for target shooting
This lower parts kit features a clean-breaking trigger that’s just slightly lighter than mil-spec.
Bottom Line
As you can see, different AR-15 kits contain a variety of different components depending on what you’re looking for. If you like a particular lower receiver, start from there.
If there’s an upper that strikes your fancy, use it. If you’re happy with your frame but want to upgrade your rifle’s mechanical parts, consider a rebuild using premium parts.
The most complete kits you’re going to find are the Brownells upper receivers, which are essentially AR-15 complete rifle kits (less receivers). Add a lower and a pistol grip, and you’re ready to go.
As we’ve mentioned in a couple of the reviews, complete lowers are considered firearms under US law. Unlike other rifle parts, they can only be shipped through a registered FFL dealer.
And that about covers it. We hope our reviews have helped you become a more educated customer. With this many options, it’s easy to get started on your own custom AR build, no matter what features are most important to you.
Check out all the other AR-15 articles put together by our expert team here at Guns & Safety Reviews;
The Review
Best AR Build Kits
We've reviewed the best AR build kits on the market today to help you choose which one to buy.
Review Breakdown
- Tactical Receivers Build Kit
- Premium Receivers Build Kit
- Premium Upper Assembly Build Kit
- Upper Receiver Assembly
- Billet Rifle Lower Receiver
- Lower Receiver Kit
- 80% Lower Build Kit With Buttstock
- DPMS Lower Parts Kit
- BCM Lower Parts Kit
Best AR Build Kits DEALS
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