Thinking about making your own AR at home using an AR build kit and saving some money? Get the scoop here first before buying the parts and tools you need.
Should I Buy or Build an AR?
That depends. If you’re familiar with how a rifle works, you may be able to save money by building. If you aren’t, it might cost you more and you might not end up with a very good rifle at the end of it.
However, if you shop smart for a reasonably priced AR build kit and take your time with the build, you can make customizations along the way that you wouldn’t be able to get from a factory rifle.
Is It Cheaper to Build from Scratch?
It is if you shop wisely for sales and bundled deals. Also, starting with a reasonably priced AR build kit (or a lower parts kit, lower, and assembled upper) can save you. It depends, though.
What Comes with an AR Build Kit?
That depends on the AR build kit in question. Some will come with all the parts you need, less the lower receiver, which is serialized and regulated by the ATF as the actual “firearm.”
For instance the following build kit available on our website comes with:
- A fully assembled upper (stripped upper, barrel, dust cover, forward assist, flash hider, gas block and tube, handguard, bolt carrier group, and charging handle)
- Trigger and guard
- Hammer
- Pistol grip
- Bolt catch and release
- Mag catch and release
- Buffer tube, buffer and spring
- Castle nut
- Sling adapter
- Stock
- All takedown pins, springs and hardware
As you can see, this AR build kit comes with everything you need minus the lower receiver itself (which requires an FFL transfer) and a magazine - so it really has pretty much everything.
What Is the Best Caliber for an AR?
That depends on your intended purposes. Most shooters build around 5.56 or .223, because these cartridges produce little recoil, are flat shooting, widely available and affordable, and have a myriad of sporting, defensive, and competitive applications.
However, there are many other popular AR calibers, including but not limited to .308, .350 Legend, .300 BLK, and 7.62x39mm, to name just a few.
What’s the Difference Between an AR Upper and Lower?
Unlike many firearms, which have a single distinct receiver that “accepts” all other parts (hence the name) AR-style rifles have an upper receiver and a lower receiver. Each has associated components and the two must be joined together with takedown pins to assemble a functioning rifle.
What Comes with a Lower Parts Kit?
If it is a complete lower parts kit, it should generally come with:
- Safety selector
- Mag catch
- Bolt catch with plunger, spring and roll pin
- Buffer tube system with detent plunger and and retainer spring
- Takedown and pivot pins
- Trigger and components, plus trigger guard
- Hammer and components
- Pistol grip, screw, and washer
- Disconnector and components
- And all other hardware, including pins, springs, and detents
What Is an 80% Lower?
An 80% lower, also known as a receiver blank or an 80 lower, is a lower receiver that has not had critical parts/areas machined out of it, and so it cannot receive a trigger or trigger components, or the fire controls. As a result, an 80% lower cannot be used to assemble a functioning rifle until it has been completed with a jig and a drill, router, or drill press.
An 80% lower differs from a stripped lower in that a stripped lower is complete and can, in its current form, be used to assemble a functioning firearm.
What Do I Need to Complete an 80% Lower?
If you want to complete an 80% lower for an AR build project, you will need an appropriate jig, which will serve as a template, along with a drill, drill press, or router, and appropriate bits.
Are 80% Lowers Legal?
There are many states in which 80% lowers are not legal, including New Jersey, Connecticut, New York, Rhode Island, Washington, D.C., and Washington state. They are also heavily regulated in California.
This, however, is not legal advice and the legal landscape is changing all the time, so if you have questions, consult a firearms lawyer in your state.
What Is an Assembled Upper? What Comes with It?
An assembled upper consists of a stripped upper receiver assembled with all of the upper parts that are required to assemble a functioning rifle. This includes a barrel, handguard, gas system, bolt carrier group, forward assist, dust cover, and charging handle. If the barrel is threaded it should also include a muzzle device, commonly a flash hider.
Take note of what’s included, though, as sometimes bolt carrier groups, dust covers, forward assists, and charging handles are not.
Why Would I Want to Start with a 5 Inch AR Upper?
A 5 inch AR upper is a popular size for those looking to build AR pistols, which are compact, alternative builds to full-size rifles, but often in the same chambering.
How Long Does It Take to Build an AR with a Build Kit?
That depends on how much experience you have, but if you start with a completed lower receiver (not an 80% lower) along with an assembled upper or a complete build kit, if you have good instructions, it should only take a few hours.
If you do the whole thing from the ground up with an 80% lower, expect it to take substantially longer. The project can still likely be completed within a day, though.
Which Handguard Is Best?
There are three main common styles of handguards: Pic rails (which usually form quad rail uppers) and KeyMod and M-LOK rail systems.
Pic rails are durable and have a huge amount of accessories made for them. KeyMod and M-LOK rail systems are newer and fewer accessories are available for them, but they are also a lot lighter and more comfortable to shoot without gloves.
Get what works best for you.
Getting Started with an AR Build Kit from MCS Gearup
Getting ready to start your project with an AR build kit? Hopefully you found the answers to your questions here, but if not, feel free to reach us at Sales@MCSGearup.com. We can help you find the parts you need to complete your home build.