Building an AR-15 lower receiver from scratch is easier than you think – you just need the right tools. If you’ve read this far into the process, we’ll assume you’re already convinced that you want to become a proud homebuilt gunsmith. So, let’s dive right into the must-have tools for completing an 80 lower:
- 80% Lower AR-15 Jig
Your jig is the heart of the entire operation. Without a jig, you simply can’t build an 80% lower into a finished AR-15 receiver. An 80% lower jig secures your lower in place and it even pre-measures the holes you need to drill. It also guides your cutting bits along, making the machining process easy and guesswork-free.
Most 80% lower jigs are universal and easy to use, but we recommend the 5D Tactical Router Jig PRO or the Easy Jig Gen 2. These are the two most popular 80% lower jigs available, and for good reason: They’re quick and easy to use, they’re well-built, and they reduce the total machining process dramatically.
- 80% lower Tooling
Most 80% lower jigs include the necessary tooling, but not always. If you buy a jig by itself, you’ll the following tools:
- (1) Carbide End Mill Bit
- (1) 3/8” Drill Bit
- (1) 5/32” Drill Bit
- (1) 21/64” Drill Bit
We also recommend investing in an Armorer’s Wrench. This is a wrench specifically designed for seating your barrel and castle nut, as well as installing your buffer tube. Lastly, you should invest in a quality set of roll pin punches. Trust us, they’ll make final assembly of your AR-15 lower much, much easier.
- Hand Router
Obviously, you won’t be turning those end mill bits and drill bits by hand – you’ll need a quality, compact hand router. To make things easy we’ve offered up a universally accepted router that works well with all our 80% lower jigs, and that’s the Port-Cable Router. This little guy spins at a robust 31,000 RPM and weighs about 3 pounds. It’s just heavy enough to remain stable and secure, but light enough to maneuver easily. It even includes a handy little wrench to swapping out those drill bits!
- Table Vice
Face it, trying to install a barrel, gas system, and those tiny little roll pins by hand is a pain. You’ll want a secure, desk- or standing-height table vice to secure your AR-15 lower receiver and upper in place while you work.
- AR-15 lower Parts Kit
We saved the most obvious for last! You’ll need an appropriate AR-15 lower parts kit, and we’ve got plenty of them. The AR-15 Lower Parts Kits we sell will include everything you need to turn that hunk of stripped receiver into a real firing mechanism. Want everything in one kit? Pick up our Parts Kit that includes a butt stock and buffer tube assembly! Everything is mil-spec and ready to go out of the box.
Building an 80% lower takes a little bit of patience, muscle, and finesse. Those last two don’t usually go together, which is why the former is so important. Trust us, there is a small learning curve. But, once you’re familiar with this process, you’ll be turning 80% lowers into finished AR-15 lower receivers in less than one hour! It’s all about having the right tools.