The Best AR 15 Build Kit for Completing a New Rifle This Year

Last Updated on January 22, 2022.

Building an AR-15 is cool. And, building an AR-15 just gets cooler when everything goes together easily.

An AR-15 build kit helps ensure that everything goes as planned, and you don’t spend much (if any) time in the garage scratching your head, wondering why things don’t fit the way they should.

AR-15 build kits come in all varieties and levels of completeness, from just a few parts to nearly an entire rifle that you just need to assemble. What you buy depends on what you need.

The Top AR-15 Build Kits on the Market

Our Best Choice

DPMS AR-15 5.56mm 16” Oracle Rifle Kit

DPMS AR-15 5.56mm 16” Oracle Rifle Kit

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  • Almost a complete rifle.
  • Some components come assembled.
  • Kit builds out into one of the highest rated budget rifles on the market

SPOILER—if you need just about everything, get the DPMS AR-15 5.56mm 16” Oracle Rifle Kit. It’s probably the most complete AR-15 build kit on the market, it’s affordable, and you get a pretty darn good rifle when you’re finished.

If you need something less than an entire rifle, stick around. We’ll cover all the best build kits, from all the different levels of completeness.

The Best AR 15 Build Kit Reviews: Getting Everything Together

Our winning (and most complete) kit is up first. The runners up are sorted in order of price. The most budget compatible are up first. The most budget derailing are near the end.

Time to find out how everything fits together.

1. DPMS AR-15 5.56 16” Oracle Rifle Kit

DPMS AR-15 5.56mm 16” Oracle Rifle Kit

Overall Best AR-15 Build Kit

The DPMS AR-15 5.56 16” Oracle Rifle Kit is almost a complete rifle once you get everything assembled. What does this kit turn into? The DPMS 5.56 Oracle A3 Rifle.

The big deal with this kit is that it includes more components than any other kitYou get everything except the lower receiver. That means you get an upper receiverstockbarrel, and all the necessary hardware to build your rifle.

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And, some of the assembly is completed for you.

The forward assist and dust cover come installed on the upper receiver. And, the gas block comes mounted on the barrelThe bolt carrier and bolt come assembled in some kits. But, for some reason, not every kit includes an assembled bolt carrier group.

Even though this is a kit, it builds out into a solid rifle. The DPMS Oracle is one of the highest rated budget AR-15 rifles on the market. You get a good rifle and a great platform to upgrade, if you want.

There’s no lower receiver included with this kit. The lower receiver is a serialized part. So, it needs to be purchased separately.

Also, occasionally there are fitment issues with these kits. It’s not common, and the kit can usually be modified slightly to get it to go together. But, there have been reported quality control issues.

But, overall, this kit offers exceptional value. For a little over $600, this kit can deliver a complete and operational AR-15.

Having spare parts in your kit is very important for every firearm enthusiast and will come in handy when time comes you need it.


  • Almost a complete rifle.
  • Some components come assembled.
  • Kit builds out into one of the highest rated budget rifles on the market.


  • No include lower receiver.
  • Occasional quality control issues.

2. Aero Precision AR-15 Upper Parts Kit

Aero Precision AR-15 Upper Parts Kit

Budget AR-15 Build Kit for Upper Receiver

If you just need the exterior parts to complete your upper receiver, the Aero Precision AR-15 Upper Parts Kit solves that problem for very few dollars.

This build kit includes all the hardware for your upper receiver: dust cover, forward assist, and all the springs and pins needed to install them.

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All the parts are either machined or forged. Nothing is cast. So, none of these parts will be a weak point in your build.

And, everything is hard coat anodized to match the finish and corrosion resistance on your upper receiver.

The only struggle with this parts kit is that Aero Precision parts tend to fit best in Aero Precision receivers. These parts will fit into upper receivers from other manufacturers. But, modification is necessary for a perfect fit in some upper receivers.But, for the money, this Aero Precision parts kit is a slam dunk for anyone who needs just a few upper receiver parts to complete their build.


  • Includes everything you need to get your upper receiver running.
  • All parts are machined or forged.
  • Hard coat anodizing matches the finish on almost any upper receiver.
  • Extremely affordable.


  • Requires fitment to work with some upper receivers.

3. CMMG AR-15 Gunbuilder’s Lower Parts Kit

CMMG AR-15 Gunbuilder’s Lower Parts Kit

Budget AR-15 Build Kit for Lower Receiver

The CMMG AR-15 Gunbuilder’s Lower Parts Kit enables you to complete your lower receiver for the lowest possible price.

Now, this isn’t a complete lower receiver build kit. It lacks a pistol grip, stock hardware, trigger, and trigger guard. But, it gives you all the hardware you need to make your lower receiver functional, once you have all the big pieces in place.

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This kit comes with all the takedown pinssafety selectorbolt catchmagazine release, and all the associated springs and pinsIt’s all the latches, levers, and buttons you need for a completely operational lower receiver.

All the parts are machined or forged. And, everything is hard coat anodized to match your lower receiver. So, these parts are just as strong—if not stronger—than your lower receiver. And, the finish will hold up just as well as the finish on your lower receiver.So, if you need the small pieces to finish your lower receiver, or if you just want to upgrade your hardware, this CMMG kit will get you what you need for the minimum price.


  • Includes all the operating parts you need for your lower receiver.
  • Everything is machined or forged. No cast parts.
  • All parts are hard coat anodized to match the finish on most lower receivers.


  • Not a total lower receiver completion kit. Some furniture is not included.

4. Critical Capabilities LLC AR-15 Lower Parts Kit

Critical Capabilities LLC AR-15 Lower Parts Kit

Value AR-15 Build Kit for Lower Receiver

The Critical Capabilities LLC AR-15 Lower Parts Kit offers a more complete solution for those who need to complete the lower half of their rifle.

This kit comes in two variantswith a pistol grip and without a pistol grip.

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However, both kits include a trigger. And, the trigger is better than a standard mil-spec trigger. The included trigger is ground and polished in-line with the direction of the trigger movement. So, you get a much smoother mil-spec trigger press, a cleaner break, and a better platform for doing your own trigger job.

In addition to the trigger, this kit includes all the necessary lower receiver hardware. All the hardware is machined or forged to ensure that it holds up to any abuse you throw at it. And, the hard coat anodized finish is thick and matte black to match your lower receiver.

Unfortunately, this kit includes an A2 pistol grip, which is pretty much the least comfortable pistol grip you can get. 

And, a few buyers have found that the anodized finish is so thick that it makes for an overly tight fit that has to be sanded or broken in to get perfect function.

But, this Critical Capabilities build kit offers excellent performance and an upgrade for one of the most important parts of your rifle: the trigger. It’s a great deal for the money.


  • Includes an enhanced mil-spec trigger.
  • Can be purchased with an included pistol grip.
  • Machined and forged parts ensure they’re just as durable as the rest of your rifle.
  • Hard coat anodized finish is thick.


  • A2 pistol grip is not the best grip ever.
  • A few buyers have reported that the anodized finish is occasionally too thick for easy part installation.

5. Bravo Company AR-15 BCMGunfighter Enhanced Lower Parts Kit

Bravo Company AR-15 BCMGunfighter Enhanced Lower Parts Kit

Complete AR-15 Build Kit for Lower Receiver

The Bravo Company AR-15 BCMGunfighter Enhanced Lower Parts Kit gives you almost everything you need to complete your lower receiver. And, all the parts greatly exceed mil-spec standards.

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However, the star of this show is the trigger. The included trigger is the Bravo Company PNT Trigger. This trigger is machined to mil-spec standards, then ground and polished to remove any grit from the trigger press.

Additionally, the trigger components are covered in a nickel teflon finish that reduces friction even more and ensures that the break is always clean. This trigger offers an exceptionally smooth press and crisp break that maximizes accuracy for both tactical and long range shooting.

Also, this Bravo Company parts kit includes the BCM Pistol Grip Mod 3. It’s a huge step up from an A2 grip, and gives you a consistent grip and better accuracy from shot to shot, right out of the box.

Then, there are all the lower receiver components. Every component is precision machined to mil-spec standards, and heat treated to maximize the lifespan of each piece. Lastly, the hard coat anodizing is more durable than that of most lower receivers.

The whole kit is a bit pricey. But, if you have an empty lower receiver you need to fill up with parts, this parts kit gives you the most durable components on the market.


  • Includes an excellent tactical trigger.
  • Included pistol grip is a huge upgrade over an A2 grip.
  • All the components are machined, heat treated, and inspected to ensure they fit any mil-spec lower receiver.
  • Hard coat anodizing is impressively thick and durable.


  1. No included buttstock.
  2. Expensive.

6. Brownells AR-15 Tactical Receivers Build Kit

Brownells AR-15 Tactical Receivers Build Kit

Tactical AR-15 Build Kit

The Brownells AR-15 Tactical Receivers Build Kit requires some work. But, once you’re done, you’ll have a complete upper and lower receiver, minus the bolt carrier group.

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First, this kit includes both the upper and lower receivers.

The upper receiver is a stripped Aero Precision upper receiver. It’s forged from 7075 T6 aluminum for durability and longevity, and offers M4 feed ramps for reliable operation.

Then, the lower receiver is an Anderson Manufacturing 80% lower receiver. The lower receiver is also forged from 7075 T6 aluminum. However, it requires machining to complete. And, it’s shipped without any finish on it. So, you’ll need to anodize or cerakote it.

But, if you build a rifle with this build kit, you’ll end up with a really respectable and dependable AR-15.

Lastly, all the parts—the upper and lower receiver parts kits—are DPMS parts kitsThese are mil-spec parts that match up nicely with the upper and lower receiver.

This parts kit also includes a pistol grip. yes, it’s an A2 pistol grip. But, it works. And, once you’ve got this kit assembled, all you really need is a barrel and buttstock.

If you’re looking for a kit that will get you most of the way there, while leaving plenty of room for customization, this kit is a super cost efficient way to go.


  • Includes both upper and lower receivers.
  • All hardware meets or exceeds mil-spec standards.
  • Includes almost everything you need to complete an AR-15 rifle.


  • Requires machining and coating to complete.
  • Included pistol grip is an A2 pistol grip.

7. Brownells AR-15 Upper Build Kit

Brownells AR-15 Upper Build Kit

AR-15 Build Kit for Complete Upper Receiver

The Brownells AR-15 Upper Build Kit is unique in that it includes all the parts you need to finish your AR-15 upper receiver.

This kit is built on an Aero Precision stripped upper receiver. It’s an incredibly durable upper receiver that’s forged from 7075 T6 aluminum. This upper receiver is also equipped with M4 feed ramps for more reliable operationIt’s a backbone that will deliver incredibly long service life and reliability for your completed rifle.

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The bolt carrier group is an Anderson Manufacturing M16 5.56 Bolt Carrier Group. This bolt carrier group is like the Honda of M16 parts. It’s not flashy. But, it’s affordable, and it runs reliably. That’s just about all you can ask for from a bolt carrier group.

Then, all the parts—the dust cover, the forward assistcharging handle, and all the pins and such—are DPMS mil-spec parts. Again, these aren’t special. But, they meet the mil-spec standards and will hold up for as long as the rest of your rifle.

Even though it’s nothing special, this Brownells AR-15 build kit gives you a dependable upper receiver that you can marry up with any barrel and furniture to get a reliable rifle that won’t hold you back and improve your shooting accuracy.


  • Includes everything you need for a complete upper receiver (minus the barrel).
  • Forged upper receiver with M4 feed ramps is durable and reliable.
  • Bolt carrier group delivers reliable operation.
  • All exterior parts meet mil-spec standards.


  • Hard coat anodized finish is not the same on all components. Creates a bit of a mismatched look.

Completing Your Build

Building an AR-15 is an incredibly fun and rewarding experience. Build kits simply take some (or all) of the headache out of the build process. So, you can quickly put your rifle together and get out there and see what you’ve got. Goes best with an affordable multi-tool, if you ask me.

If you're feeling lazy, might as well just get an already completed one. Just go here for ar-15 rifle definitive buying guide.

DPMS AR-15 5.56 16” Oracle Rifle Kit

DPMS AR-15 5.56mm 16” Oracle Rifle Kit

If you want a build kit that has almost everything you need for an entire rifle, get the DPMS AR-15 5.56 16” Oracle Rifle Kit. It’s affordable, and you only need to purchase one part to get a complete rifle that’ll run great.

Now that you’ve seen all the corners you can cut by working from a build kit, stop thinking about it, and get your next rifle built.

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