cc-settings-icon BUILD AT HOME
80% Arms sells AR-15 and .308 80% Lower Receivers, 80% Lower Jigs and other accessories which allow you to legally build a firearm at home in most states.
We utilize state of the art 5-axis CNC machines to mill all our .308 and AR-15 80 percent lower receivers to incredibly precise tolerances using premium billet aluminum.
We also offer our patented AR-15 and .308 Easy Jigs which is the first 80% lower jig that makes it ridiculously easy for a non-machinist to finish their 80% lower in under 1 hour with no drill press required.
Products manufactured by 80% Arms carry a lifetime warranty against manufacturing defects. We will promptly replace or repair any product that we determine to be defective.

Complete 16" .223/5.56/300BLK AR-15 80% Build Kit

Barrel Selection for 16" .223/5.56/300BLK Upper
Muzzle Selection for .223/5.56/300BLK
Handguard Selection
Calculated at Checkout
Out of stock
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Rest assured, we are shipping all orders in accordance with the ATF rule and due to high demand it is taking us some time.
For concerns on how the rule affects our products view our ATF RULE FAQ page.

This complete 80% AR-15 build kit contains all the necessary high-quality parts to build your AR-15 at home! We removed all the guesswork and packaged the necessary parts to build your AR-15 in one, easy to purchase, complete 80% AR-15 build kit. There are barrel and handguard options available, allowing you to customize the look and performance of your rifle. Buy as a complete kit and save money versus purchasing the necessary items separately!

Our Complete AR-15 80% Build Kit Contains:

  • 16" AR-15 Upper Receiver - Select Barrel and Handguard Options Above!
  • Black Nitride .223/5.56/300 BLK Bolt Carrier Group
  • Standard Charging Handle
  • Mil-Spec Stock
  • 6-Position Carbine Buffer Tube Kit
  • Billet Aluminum 6061 AR-15 80% Lower Receiver
  • Mil-Spec AR-15 Lower Parts Kit

About the options:


Barrels available in this kit are 16" length, with a 1:8 twist rate. Generally speaking, the twist rate is a common factor when considering the primary purpose of the rifle, and which ammo you will shoot as it correlates to bullet weight. A 1:8 twist rate is regarded as the best "general purpose" twist rate for a multitude of sporting purposes because it has been shown to accurately shoot bullets in the wide range of 50-80 grains. Read our blog post on twist rates for more info.

.223 Wylde or 5.56mm NATO?

A common question, with a simple answer. Both the barrel options included in this complete 16-Inch AR-15 build kit will safely shoot 5.56mm NATO or .223 Remington ammunition. For some, it's a matter of preference. However, the .223 Wylde barrel will shoot .223 Remington with better accuracy than a barrel chambered in 5.56mm NATO, but can also withstand the pressure load of 5.56mm NATO. The popularity of .223 Wylde chambered barrels as somewhat of a "hybrid" chamber has grown in the past years, bringing the price point of the .223 Wylde down to that of the common 5.56mm NATO barrel.

Stainless or Parkerized?

Again, this is much a matter of preference and the general look desired. In this complete 80% AR-15 build kit, both the Parkerized high-carbon steel and 416R stainless steel barrels will provide years of accurate performance. Parkerized barrels have a metal finishing process applied to provide a long lasting and durable flat black surface finish. Stainless Steel barrels are constructed of 416R Stainless Steel and provide the satin silver look that many enthusiasts prefer.

Muzzle Device

A2 Style Flash Hider or Compact Muzzle Brake? While mostly a matter of looks or preference, some states have outlawed A2 Style Flash Hiders or consider them to be "evil features", contributing toward what may or may not be considered an "assault rifle" under the definition of state law. Be sure to read and understand your local laws. Aside from the legality, there are benefits in looks and performance when choosing a Compact Muzzle Brake. Muzzle brakes, besides looking cool, divert the gases exiting the barrel in such a way that reduces recoil and muzzle rise, and can improve follow-up shot speed. Check out our blog post on muzzle brakes for more information.


When it comes to choosing a handguard for your new rifle, there is a delicate balance of form and function. For starters, our M4 Style Handguard with exposed gas block is lightweight, budget-friendly, and perfect for those adding a receiver-top optic. Our lightweight M-LOK free-float handguard designs are available in 12" and 15" lengths. While mostly a matter of personal preference, these attractive handguard styles can offer functional performance for all of your shooting needs.


Shipping Restrictions: This item is restricted from shipping to California, Connecticut, New Jersey, New York, Washington D.C, Washington, Hawaii, Oakland City, Unincorporated Boulder County Colorado (Allenspark, Coal Creek Canyon, Eldora, Eldorado Springs, Gold Hill, Gunbarrel, Hygiene, and Niwot), City of Denver Colorado, City of Philadelphia Pennsylvania, Maryland, Illinois, and Rhode Island