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.
cc-gun-icon INCREDIBLY PRECISE
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.
cc-hand-icon RIDICULOUSLY EASY
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.
cc-thumbs-icon 100% SATISFACTION GUARANTEED
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.
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Gun Build Kits

Build Your Own AR with Our 80% Lower Rifle Build Kits

If you’ve ever wanted to build your own AR from the ground up, our 80% lower build kits are the ultimate solution. These 80% build kits include everything you need to assemble a fully custom AR15, AR10, or AR9 pattern rifle. Our kits are designed for builders who want hands-on experience, ultimate customization, and the satisfaction of creating a firearm that’s truly their own.

What Is Included in an 80% Build Kit?

Every rifle build kit includes all the components to complete your AR project, with the exception of a fully milled lower receiver. Our 80% lowers are unfinished and require milling to become a serialized, functioning firearm—keeping you in full control of your build.

Available Options

  • Calibers: 5.56 NATO / .223 Wylde, .300 Blackout, 9mm, .308 WIN, 6.5 Creedmoor
  • Barrel Lengths: Ranging from compact pistol builds to full-length precision setups
  • Handguards: M-LOK, KeyMod, and quad rail options
  • Muzzle Devices: Flash hiders, compensators, and suppressor-ready threads

Why Choose Our 80% Lower Build Kits?

  • Full customization with professional-grade components
  • The perfect starting point for learning AR platform assembly and gunsmithing
  • High-quality parts guaranteed to last a lifetime

Whether you’re a first-time builder or a seasoned enthusiast, our 80% lower build kits give you the freedom to create your AR with confidence.

Shop our 80% Build Kits today and start your custom AR project!

Need some more info on if a build kit is right for you? Check out our blog!

All products backed by our lifetime guarantee!