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In this article, we’re talking about building your own AR-15 with a build kit.
A build kit is a great tool for a first-time AR user and an easy way to get started in this regard.
Quality build kits will have everything you need to build an AR-15, and we’ll run you through some of the top choices on the market.
At a Glance: Our Top Picks for Best AR-15 Build Kits
- OUR TOP PICK: PSA 16" M4 5.56 NATO
- RUNNER-UP: PSA Gen2 16" 5.56 NATO 1:7 Mid-Length
- BEST AR-15 LOWER BUILD KIT: TRYBE Defense AR-15 Mil-Spec Complete Lower Parts Kit
Comparison of the Best AR-15 Build Kits
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What Do I Need to Build an AR-15?
Before we get started, let’s run down the basics, we’re going to outline what is needed to build an AR-15, in terms of both parts and tools.
What Parts Do I Need To Build an AR-15?
Various parts go into a standard AR-15:
Upper/Lower Receivers
Receivers are given their name because they “receive” other components of a gun. They act as frames for the gun overall, where you can add and customize your parts. AR-15s are made with upper and lower receivers, which make up the overall frame of the gun.
Most receivers work with any AR, but build kits include receivers that are guaranteed to fit together. Of course, there is a large difference in receiver quality depending on which materials are used.
Many build kits do not include a stripped lower receiver, because this is the part that qualifies as the “gun”, and will need to be registered upon purchase.
Grip
The grip, or pistol grip, is attached behind the trigger and provides an area to hold the gun comfortably. Grips are made with different angles, sizes, materials, textures, and other factors that determine comfort level and usability.
Barrel
A gun’s barrel is the straight tube through which the bullet travels. It is where gas expands to shoot out the projectile and is thus very important in any gun build-kit.
Barrels differ in their functionality based on many different factors, including size, length, durability, twist rate, velocity, accuracy, and more.
Trigger
A trigger is of obvious necessity to fire a gun. Most drop-in triggers can be easily installed to an AR-15 by simply taking out the old one and replacing it. Drop-in triggers have all the internal components of the trigger included.
Stock
The stock is the piece that protrudes from the back of the gun and is meant to rest against your shoulder for a more stable and comfortable shot.
Stocks come in fixed or collapsible varieties. Fixed stocks have a fixed length, and should be bought based on how the user is comfortable shooting. Collapsible stocks can be adjusted for length, and are great if you prefer to mix up your shooting form, or if multiple people might use the gun.
Charging Handle
A charging handle on an AR is used to move the bolt, striker, or hammer into the “ready” position. They can also eject spent shells, or check the gun for blocks. Any quality AR kit will come with a charging handle.
Gas System
Gas is what is used to shoot, eject, or chamber rounds within the AR-15. As such, a proper gas system is very important to a functioning gun. Any build kit will come with a gas system. Most build kits will come with direct impingement gas systems, which is considered standard.
Handguard
A handguard is a piece that allows the user to grip the front of the weapon. This allows more control over the weapon itself, for increased accuracy and maneuverability. It also provides an essential service in insulating the user against the heat that builds up in the barrel.
What Tools Do I Need to Build an AR-15?
Not a lot of tools are necessary to build an AR-15. Most pieces of an AR-15 are attached using pins, which are devices that are inserted securely to hold each piece in place. You may also need a screw or screwdriver/Allen wrench. But, generally, you won’t need more than that if you buy a proper build kit.
A build kit should give you all you need to build your AR-15 and will have all the gun components to build a functional, quality gun.
Are AR-15 Build Kits Universal?
Most properly designed AR-15 components are universal, in that they can be detached and reattached to different set-ups. Of course, there are so many different makes and models of everything that this isn’t going to be the case all the time.
In terms of a build kit, all the pieces within the kit will fit together. They will generally also be able to be swapped out with different AR-15 components. Companies prefer to build their components to work with as many AR set-ups as possible because they are in the business of ensuring that customers are able to use their products!
How to Choose an AR-15 Build Kit
Choosing an AR-15 build kit is not always an easy task. An AR is such a versatile weapon that it can come in many different forms, both in terms of quality and in terms of function (not to mention looks!). Here are some factors to consider so that you can make the right choice:
Quality
The first factor to consider in your AR-15 build kit is the quality of the components. Of course, there are so many components that it’s difficult to tell the degree of quality which they all are. Different factors might make each component a higher quality. For example, a stainless steel barrel is generally considered better than a chrome-moly barrel.
You mostly just need to consider how the whole package comes together. Read customers reviews (and our reviews!) to see whether these products stand up to the test.
Durability
Closely in line with quality is durability. Much of this is decided by the quality of the parts, but can also be decided by other factors, such as the heaviness of the components, and thickness of the metal. Once again, it’s a great idea to check out reviews to see what people think.
Your Preferences
Finally, you need a gun that’s in line with your own shooting preferences. Many factors influence how a gun shoots, such as barrel length and design, type of grip, trigger design, and much more! Evaluate all the components to see whether it matches your preferences, and we think you’ll make a great choice.
Review of the Best AR-15 Build Kits
In this section, we’re outlining the best AR-15 build kits. These are all quality kits, and we wanted to include ample variety so that you can pick one to best suit your needs:
Best Overall:
PSA 16" M4 5.56 NATO
Pros
Cons
What Recent Buyers Report
Buyers were very happy with this kit overall. They report a kit that is very easy to assemble and a gun that functions and shoots with precision. They were happy with the overall feel of the gun, and most had nothing but good things to say.
Why it Stands Out to Us
This is our top choice because it is such a good starter kit. It’s just a standard, highly functional AR kit, and most of the time that’s exactly what you want! It’s pretty “middle of the road” with all its tech specs, which just results in a well-rounded gun that is appropriately weighted, accurate, and comfortable to hold. For first-time AR builders and experienced shooters alike, this is a great choice.
The Bottom Line
This kit gets our top choice because it’s exactly what most AR builders are probably looking for. A simple, functional AR that is easy to build, and it’s hard to beat the price. Just be aware that you need a stripped lower receiver to go with this package.
Runner-up
PSA Gen2 16" 5.56 NATO 1:7 Mid-Length
Pros
Cons
What Recent Buyers Report
Most buyers were extremely satisfied with this product. Reviews were almost all great. Many buyers spoke to quality parts which they didn’t expect to receive at that price-point. Even beginner users were able to easily assemble this gun with their stripped lower, thanks to intuitive design principles.
Why it Stands Out to Us
This may be a more expensive item but it is justified. Simply put, it has the added quality which more than justifies the bump in price. This is a high-quality AR, built with quality components, and built to last. We specifically like the Nitrided Gas Tube and the M-Lok Free Float rail on the barrel. It has many features that you’d expect of a premium AR package for a fair price tag.
The Bottom Line
If you’re looking for a more premium option without the premium price tag, consider this one. Easy to build, high-quality materials, and lifetime warranty. All-around great package.
Best AR-15 Lower Build Kit:
TRYBE Defense AR-15 Mil-Spec Complete Lower Parts Kit
Pros
Cons
What Recent Buyers Report
Most buyers were happy with this lower build kit. Most reported a straightforward build, and they especially appreciated the handy parts-checklist within the package. Some customers had a few issues with parts that were prone to bending, but it’s not clear how prominent this issue is.
Why it Stands Out to Us
We like this package for its no-nonsense design. If you’re looking for all the parts to wrap up your lower receiver build on your AR, this has all the basic components you need. This is a full kit, which has everything you will need to complete your lower build. The checklist allows you to easily keep track of installation, to ensure you do not miss anything. As far as quality, the parts are pretty middle of the road, which is more than enough for beginner AR builders.
The Bottom Line
Just a quality, no-frills lower parts package to finish your AR build. The package has what you need, and everything is clearly marked and fairly priced.
Best AR-15 Upper Build Kit:
CBC Industries AR-15 Complete Upper Receiver Pistol Kit
Pros
Cons
What Recent Buyers Report
Buyers were overall satisfied with this product. Buyers who were looking for a short-barreled AR came away happy. They had mostly only good things to say about the assembly process and the end result.
Why it Stands Out to Us
If you’re looking for a short-barreled AR for that extra maneuverability and control, then this might be what you’re looking for. Just be sure that these are legally allowed within your jurisdiction.
As far as the gun itself, it’s an all-around solid package. It’s not the most durable gun (for example, chrome-moly isn’t as long-lasting as stainless steel), but it’s great for what you can expect within this price range. It’s a highly functional short-barreled AR, which might be suitable if you want to give up some accuracy and velocity for that extra maneuverability and portability.
The Bottom Line
This is a quality short-barreled AR kit. It is very fairly priced for what’s included in the package, and assembly is simple and straight forward. Just be sure you are looking for an AR with a barrel this short, as it is quite a specialized piece of equipment.
Editor's Pick
PSA 16" Mid-Length 5.56 NATO 1:7
Pros
Cons
What Recent Buyers Report
Most buyers were extremely happy with this product. Most reviews were glowing, and they spoke a lot about just how easy this gun was to put together. Buyers were a mix between first-timers and experienced AR users, and most came away quite happy with this kit. The result was a quality gun that met their expectations.
Why it Stands Out to Us
We like this kit because it’s a solid, well-rounded option for a fair price. We especially love that it’s a lightweight option while maintaining a mid-sized barrel for extra precision and velocity.
It’s not the most premium option on the market, so it doesn’t have the durability of top-tier ARs, and might be better suited for less experienced builders. But, for the price, it offers excellent functionality and quality, and it’s so easy to put together and use. Just a solid all-around choice.
The Bottom Line
Another solid, functional, well-rounded AR kit for beginners and experienced users alike. Building the AR is incredibly simple, and this kit has everything you need to get the job done (save for a stripped lower, but that’s pretty typical with most kits).
AR-15 Build Types
As you can see from our list, the AR-15 is a versatile type of gun, which means there are many different build kits. While there are no “official” categorizations of AR-15 kits, they can generally be divided into a few types
Lower Build
A lower AR build will generally contain all the components to attach to a strapped lower, building the bottom section of the AR. The list of components is long, but is pretty standardized, and should fit any strapped lower. Above, we examined our favorite AR-15 lower build kit
Full Build Kit
A full build kit typically contains everything you need for a complete AR-15, save for the stripped lower. It has an upper receiver, barrel, pistol grip, and everything else you need to build a functioning gun. It typically comes with detailed instructions and is intuitive even for beginners.
Quality Differentiations
While this is a more general category, the main factor that differentiates different build kits is quality. Simply put, there are so many degrees of quality that you can expect with an AR-15 build kit and so many different components to evaluate. Be sure to do careful research and to read reviews to ensure that your kit will meet your expectations.
Comparison Overview
In this section, we’re going to compare and contrast some commonly contested or confusing areas of AR-15 gun ownership.
Build vs Buy AR-15
Buying vs. building an AR-15 comes down to your preferences. You can get a quality gun either way, and there is a lot of variabilities when it comes to the quality of either area.
The differences are obvious, and building might be preferred by more hands-on gun owners, while buying might be preferred by those who just want the finished product.
Building an AR has the added benefit of teaching you the different components of the gun so that you can make further modifications in the future as you see fit.
Carbine vs Mid Length AR-15 First Build
For most AR-15 builds, you’ll want a mid-length gas system, but this is not always the case.
The gas system is meant to fit with the length of your barrel. The length of the gas system is meant to increase as the barrel increases.
A carbine is ideal for a barrel length of 10-18 inches, while a mid-length is ideal for a barrel length of 14-20 inches. Most of the time, the AR-15 barrel will be more suited to a mid-length gas system, but it does depend on which barrel you are using. Barrel length remains your primary consideration.
How to Build an AR-15 With a Build Kit
In this section, we’ll provide you with tips and tricks for building your AR-15 upper and lower. We’ve included handy video guides, as well as simple explanations for what you should expect.
How to Put Together an AR-15 Lower
An AR-15 lower contains all the parts which are to be attached to the strapped lower, to form the lower portion of the AR-15 gun.
Generally speaking, you need to follow the instructions exactly on the product you choose. It’s difficult to explain the exact process step by step here, as it will vary slightly according to the parts you purchase. Most of the time, the process is quite similar, and you can find a detailed explanation in the video below.
Tips On How to Build Your Own AR-15 Upper
An AR-15 upper comprises the upper receiver and the components which attach to it to make the gun function. Similar to the lower, it’s all about following the instructions in the kits you receive.
Most of the time, it is highly intuitive and can be done mostly with pins, and simple screws. An AR-15 kit will contain all the parts you need to do the job, and most of the time will contain everything except a stripped lower. It’s all about following the instructions exactly on your specific kit. This ensures that you build a gun that is functional and safe.
For a more detailed explanation, check out the video below.
Conclusion
Thanks very much for reading our guide to building your own AR-15. As you can see, it’s a very accessible process. Even beginner builders can build their very own AR, and it’s a great way to learn about the components of these guns. While you can certainly buy a completed AR-15 on its own, many opt to build because it’s a fun process and the end result is truly theirs.
People Also Ask
Before we wrap up our article, let’s check out the top questions about AR-15 kits and general AR-15 applications.
Why Build Your Own AR-15 Kit?
Most people build an AR-15 purely for the satisfaction of building something themselves! It also has the added benefit of building something to your exact specifications. You are even free to swap out certain parts if you want.
Is it Cheaper to Build an AR-15 or Buy One?
It depends on the parts you buy and the quality you are going for. Generally speaking, it is more expensive to buy a pre-built AR-15, because you are paying for assembly as well. That being said, if you build an AR-15 of only premium components, then you can expect to pay more.
How Hard Is it to Build an AR-15?
It is not necessarily hard, but it is precise. You need to follow the instructions exactly to be sure you build a gun that is functional and safe. The important part is just following the instructions exactly.
How Long Does it Take to Build an AR-15?
It depends on how experienced you are. Experienced builders can put one together in 30 minutes – 1 hour. First time builders, it might take a few hours as they go through all the instructions.
On an AR-15 Build, What Should Not Be Skimped On?
Generally speaking, we wouldn’t skimp on the barrel or the trigger, but it’s a good idea to be sure that all your gun components are reliable. A gun needs to be reliable and safe, so it’s difficult to recommend “skimping” on anything. That being said, quality components are available at affordable prices, as you can see in our list above.
What Calibers Can You Build an AR-15 Pistol?
AR-15s can be adapted to use many different calibers. The most popular are probably the 5.56 and the .223. However, other popular calibers include the .300 and the 7.62x39mm.
How Much Does it Cost to Build an AR-15
It depends on the kits that you buy. You can typically get a quality AR kit for about $400-$800, but you’ll still need to buy a stripped lower. A stripped lower should run you about $200 as well. But it depends on the quality you want.
How to Build an AR-15 Cheap
While we don’t recommend you skimp on an AR-15 kit, you can get quality, affordable kits. Just check out our kits above!
Do You Have to Register an AR-15 You Build Yourself?
Yes, you do legally have to register an AR-15 you build yourself. However, the legally registered portion of the gun is the “lower”, which is not included in most kits. So while the gun itself must be registered, you usually don’t have to register all the parts which are included in most AR kits.
What Kinds of AR-15 Builds Are Legal in California?
California has all sorts of laws that specially regulate AR-15s. The laws are long, complicated, and murky. You can check them out here.
Can You Buy AR-15 Build Kits Online?
Yes, definitely! You can buy any of our kits online.
Do You Need a Background Check to Buy an AR-15 Build?
Most kits do not require a background check. This is because they lack the stripped lower, which is legally considered the “gun” and is the part that would require a background check. Therefore, you can buy all the components except the stripped lower without a background check (depending on your local laws of course).