Completing an 80 lower at home allows firearm hobbyists from beginners to pros to build their own custom lower receivers while maintaining full control over the build process. Whether you’re a seasoned builder or a first-time DIYer just wanting to have a fun Saturday building an AR with friends or family, having the right tools is critical for a successful and precise completion. In this guide, we’ll walk you through what we think are some must-haves and the best tools to get the job done!

1. 80% Lower Jig

An 80% lower jig is the most important tool for finishing your lower receiver. Jigs provide the necessary templates and guide plates to ensure accurate cuts and drilling. Basically a jig makes sure that you don’t take too much aluminum off during the machining process. There are two main types of jigs:

• Router-Based Jigs: These are pretty popular for their precision and ease of use.
• Drill Press/Milling Machine Jigs: Require a drill press or milling machine for more advanced users looking for added control and accuracy. Table-top drill presses work just fine.

Note: we have seen some folks build some pretty cool homemade jigs! Reach out to your local gun community members for thoughts and ideas!

2. Router or Milling Machine

• Compact Router: If you’re using a router-based jig, a compact router (such as the DeWalt DWP611 or Makita RT0701C) is an excellent choice.
• Milling Machine: For those with access to a milling machine, this option provides superior accuracy and a professional finish.

3. Drill Press & Drill Bits

• Drill Press: A drill press allows for steady, perpendicular drilling, which is crucial for accuracy.
• Drill Bit Set: A high-quality set of drill bits, including the 3/8-inch and 5/32-inch bits, is required for completing the fire control group and safety selector holes.

4. End Mills and Cutting Tools

• High-Speed Steel (HSS) or Carbide End Mills: There are many you can use, but typically a 1/4-inch and 3/8-inch end mill is typically used for milling out the internal cavity.
• Helical or Flat End Mills: Helical end mills provide smooth cuts, while flat end mills are standard for general-purpose milling. Visit your local hardware store for options or check online!

5. Vise and Clamping System

A sturdy vise and clamping system keep your lower receiver secure during the machining process. Look for a high-quality bench vise with soft jaws to prevent damage to your lower. You don’t want to go steel on aluminum, this will cause damage to the finish of the lower. You can also wrap a towel or other soft cloth around it to protect. But definitely make sure its sturdy and secure for best precision while milling.

6. Safety Equipment

• Protective Eyewear: Always wear safety glasses when using power tools. Those aluminum flakes go flying!
• Respirator or Mask: Helps protect against aluminum shavings and dust – there will be more than you think!

7. Deburring Tools and Files

After milling and drilling, deburring tools and fine metal files help smooth out rough edges and remove burrs, ensuring a professional finish.

8. Calipers and Measuring Tools

Precision is key, so having a set of digital calipers allows you to measure depth and ensure your cuts are accurate.

Notes:

Using the right tools makes all the difference. Investing in a high-quality jig, router, drill press, and safety equipment will ensure a smooth and successful build. Whether you’re a beginner or an experienced builder, having the right setup will help you complete your lower with confidence.

Build on!