AR-15 Kits, 80% Lowers & Parts: The Definitive Builder’s Hub

The AR-15 is not just America’s most popular rifle; it is the ultimate platform for modularity, customization, and private manufacturing. This is your central command for building your own. From the foundational 80% lower receiver to complete build kits and innovative 3D printable designs, we provide a curated ecosystem of high-quality, mil-spec components. Whether you are a first-time builder or a seasoned gunsmith, this is where your perfect AR-15 takes shape.

---

 Why Builders Trust Our AR-15 Components

A rifle is only as strong as its weakest part. We are committed to providing components that guarantee performance, reliability, and a perfect fit.

• Mil-Spec or Better Standard: All our core components, from receivers to buffer tubes, are manufactured to meet or exceed military specifications, ensuring universal compatibility and function.
• Made in the USA: We prioritize American-made components, from the 7075-T6 aluminum in our lowers to the hardware in our parts kits.
• The Complete Building Ecosystem: Find every component in one place. Stop hunting across a dozen websites—we have the lowers, uppers, parts kits, and jigs you need.
• Vetted for Performance: Every product we carry is selected for its proven track record of reliability and quality within the builder community.

---

Shop Our AR-15 Product Collections

(This section is the core of the page. It uses large, clickable visual cards or text blocks for clear navigation to the more specific sub-categories.)

 AR-15 80% Lowers & Jigs

The heart of your build. An 80% lower is not legally a firearm, allowing you to legally manufacture your own AR-15 receiver with a jig and drill press. We offer forged and billet 80% lowers in 7075-T6 aluminum.
[Link Button] Shop 80% Lowers →

 AR-15 Complete Uppers

The fastest way to get shooting. Our complete upper receivers arrive fully assembled with the barrel, handguard, gas system, bolt carrier group (BCG), and charging handle. Just pin it to your finished lower and you’re ready to go.
[Link Button] Shop Complete Uppers →

 AR-15 Lower Parts Kits (LPKs)

Populate your lower receiver with a complete LPK. These kits include the fire control group (trigger, hammer), safety selector, bolt catch, magazine release, and all the necessary pins and springs for a functioning lower.
[Link Button] Shop Lower Parts Kits →

 AR-15 3D Files & Parts

For the cutting-edge builder. This section features 3D printable receiver files like “The Orca,” alongside the specific hardware kits and buffer tube components needed to complete a printed AR-15 build.
[Link Button] Shop AR-15 3D Files →

---

 FAQ: Your AR-15 Build Questions Answered

Q1: What is an AR-15 80% lower?

A1: An AR-15 80% lower is an unfinished rifle receiver. Because the core fire control cavity has not been milled out, it is not legally considered a firearm under federal law. This allows an individual to purchase it and legally complete the manufacturing process themselves to create a privately made firearm.

Q2: Is it legal to build an AR-15 in the USA?

A2: Yes, under federal law, it is legal for a person who is not prohibited from owning firearms to build their own AR-15 for personal use without a serial number. However, some states and cities have enacted stricter laws, so you must verify your local regulations.

Q3: What is the difference between a complete upper and a complete rifle?

A3: A complete upper is the top half of the rifle (barrel, handguard, BCG). A complete rifle is a fully assembled firearm, including the lower receiver. Because the lower receiver is the legally defined “firearm,” complete rifles must be shipped to a Federal Firearms Licensee (FFL) for a background check, while a complete upper can be shipped directly to your home.

Q4: What tools do I need to finish an 80% lower?

A4: To finish an 80% lower, you will need a quality jig, a drill press (recommended for precision) or a hand drill, and the specific drill bits and end mill bits that are typically included with the jig. For a great visual guide, refer to the tutorials available from jig manufacturers like 80% Arms.

Q5: What does “mil-spec” mean for AR-15 parts?

A5: “Mil-spec” refers to the military specification or standard for dimensions, materials, and tolerances of AR-15 components. Parts that are mil-spec are guaranteed to be interchangeable between different manufacturers, ensuring a proper fit and function for your build.