Which 80 Lower Jig is Best for My AR-15 Build?

Posted by 80-Lower on Feb 9th 2019

Which 80 Lower Jig is Best for My AR-15 Build?

Which 80 lower jig is best for your AR-15 build? We're reviewing every jig you can buy. We'll explain the top features, pros, and cons of each one. Let's begin!

First time here? Learn what an 80% lower jig is, first.

Additional Tools Required

To finish the lower with a jig, you'll also need some basic hand tools:

  • Electric hand drill
  • Router or drill press
  • Machine oil/lubricant
  • Hearing and eye protection

Learn how to pick the best router for your jig.

All 80 lower jigs compared

There are three types of 80% jigs to choose from:

  • Disposable (polymer)
  • Single-platform
  • Multi-platform

We'll go from the cheapest (and simplest) to most expensive (and the fastest or best) jigs for this part.

#1: G150 Phoenix Polymer 80% Lower and Jig

(A detailed review/tutorial of the G150 will be linked here soon)

This first jig is interesting because it's proprietary and it's single-use/disposable. The jig only works with the included 80% lower (all other jigs do not come with a lower by default). Called the G150 Phoenix, this lower-and-jig combo is the most affordable out of all jigs and lowers.

Polymer is a common weapon material, but it's only recently been used in the AR-15. Nonetheless, it's a proven design and polymer lowers are the easiest to machine. It's perfect for beginners who want something as basic as possible. Plus, the finished lower is much lighter than a forged or billet aluminum lower. It's also compatible with all standard AR-15 parts.

The Polymer 80 G150 Phoenix 80% lower and jig, used for building a lightweight AR-15.

The Poylmer 80 G150 Phoenix lower and jig

Main Features

  • The easiest to machine
  • Zero jig setup required
  • Includes polymer 80% lower
  • Includes necessary tools/bits
  • Easier to machine than billet/forged
  • Completes lower in 30 minutes to 1 hour
  • Includes easy-to-follow written instructions

What's Needed

This jig doesn't use an adapter plate or router to mill the fire control cavity. Polymer80 recommends using the Central Machinery 8", 5-Speed Bench Drill Press. It only costs about $70. You'll need some other basic tools linked below. Most handheld routers (used with other jigs) cost around $100 to $150, so your total tool cost should come out to roughly the same amount.


This is how the Polymer 80 Jig secures your 80% lower.

As you can see, getting the polymer 80 jig ready is as easy as pressing the two jig side plates together to seat the 80% lower.

That's all you need to do for setup, then you can start milling and drilling. The red cut-out atop the jig acts as your milling guide for your drill press. The holes on the side of the jig are used to drill the trigger, hammer, and safety holes.

#2: Easy Jig Gen 1

The Easy Jig Gen 1 is the 80 lower jig that really started it all. Before the original Easy Jig, most builders needed access to a commercial drill press. The single-platform Easy Jig was the first to allow 80% lower builds with an electric drill. This is also the most affordable and the easiest-to-use 80 lower jig that can complete a standard billet or forged aluminum 80% lower.

Learn how to complete an 80% lower using the Easy Jig with this instructional guide.

The Easy Jig Gen 1 is used to complete an 80% lower for an AR-15 build project. The Easy Jig Gen 1 is the original (and the most popular) 80 lower jig.

Main Features

  • The easiest billet/forged jig to use
  • Completes a lower in 1 to 2 hours
  • Compatible with any AR-15 80% lower
  • No drill press required, only a hand drill/router
  • Built-in depth gauges (no calipers/measuring required)
  • Individual template plates, perfect for beginners
  • Simple setup with no multi-caliber configurations

What's Needed

Since the Easy Jig Gen 1 uses a router and adapter plate, you don't need a drill press or drill press vise. It's still a good idea to invest in a tabletop vise. This will prevent the jig from moving around or vibrating and shifting while you work.

  • Handheld router
  • Electric drill
  • Machining oil/lubricant
  • Optional: Vise

The Easy Jig Gen 1 uses a Drill Block (#1) atop the jig to drill the pilot holes for your fire control cavity. You'll need to drill approximately 10 holes in the fire control cavity, then you can swap out the Drill Block for the provided milling template plates (#2).

You'll also switch from the electric drill to a router, and use the provided end mill bit to finish the lower. Once the fire control cavity is completed, you'll switch back to your electric drill (#3) to complete the trigger, hammer, and safety selector lever holes. Then you've got a completed 80% lower (#4). Easy.

#3: Easy Jig Gen 2 Multi-Platform

Filling out spot #3 is the Easy Jig Gen 2 Multi-Platform, the most affordable multi-platform 80 lower jig. The Gen 2 Multi-platform builds on the Gen 1's simplicity, but it allows you to machine an AR-15, AR9, or AR-10/LR-308 80% lower, thanks to a new router plate and new, reversible side plates. The Easy Jig Gen 2 ditches the individual template plates that come with the Gen 1. It instead incorporates all cutting templates into one, single top plate.

The Easy Jig Gen 2 Multi-Platform, the most affordable multi-lower jig.

Main Features

  • Completes a lower in approx. 30 minutes
  • Requires one pilot hole for cavity (not 10 like Gen 1)
  • Compatible with AR-15, AR9, LR-308 lowers
  • Uses just one top plate for cutting and pilot holes
  • Doesn't require a drill press, only a drill and router
  • Built-in depth gauges (no measuring or calipers)
  • Swaps between calibers/platforms in a few seconds
  • Hand drill stabilizer improves drilling accuracy/stability

What's Needed

  • Handheld router
  • Electric drill
  • Machining oil/lubricant
  • Optional: Vise

We like the Gen 2 Multi-Platform because it keeps the machining process equally simple and quick across all platforms. Swapping between AR-15, AR9, or LR-308 requires just switching how the side plates and top plate are oriented.

Otherwise, the Gen 2 Multi-Platform sets up just as easily as the Gen 1. The optional hand drill stabilizer makes drilling your trigger, hammer, safety, and cavity pilot holes way quicker and simpler, too.

#4: 5D Tactical Router Jig PRO Multi-Platform

Click here for a full review of the Router Jig PRO

Finishing out our list of 80 lower jigs is the Router Jig PRO Multi-Platform from 5D Tactical. This is the fastest and arguably the most "professional" 80 lower jig. This is a multi-platform jig that sets up almost exactly how the Easy Jig Gen 2 does. The big ticket here is 5D Tactical's ReadyMILL End Mill Bit and router plate system. These two components are the secret to the Router Jig PRO's quick, clean results. Many expert machinists who've used the Router Jig PRO say it can't really be improved, it just works.

Main Features

The Router Jig PRO Multi-Platform is the fastest jig. We consider it a "professional" jig.

  • Completes a lower in 15 to 30 minutes
  • Requires one cavity pilot hole
  • Compatible with AR-15, AR9, and LR-308
  • Uses one top plate for cutting and pilot holes
  • Doesn't require a drill press, only a drill and router
  • Built-in depth gauges (no measuring or calipers)
  • Swaps between calibers/platforms in a few seconds
  • Drill stabilizers are built into side plates
  • Uses no-touch router plate guides

What's Needed

  • Handheld router
  • Electric drill
  • Machining oil/lubricant
  • Optional: Vise

The Router Jig PRO is packed with  a ton of features that make it a top pick. The PRO's top plate uses special pins and guide cavities to guide your end mill bit.

The Router Jig PRO's guide pins (left) and the guide pin cavities (right). The ReadyMILL bit (left) is over-sized, shortened, and hardened for 80% lowers.

This prevents your router and bits from ever touching the jig itself. Other jigs (like the Gen 2 and Gen 1) allow the bit's shank to touch and rub along the top plate because they act as the guides themselves. This design isn't a poor one, it just requires you to work more slowly and carefully.


That wraps up our complete 80 lower jig guide. You should be well-equipped to pick out the perfect jig for your AR build. Remember to check out our complete guide on picking the right router for your jig, and you'll be ready to build your AR at home! If you have more questions about jigs, lowers, or building your AR, reach out to us. We're here to answer your questions!

DISCLAIMER: If you are new to the world of DIY gun building, you likely have a lot of questions and rightfully so. It’s an area that has a lot of questions that, without the correct answers, could have some serious implications. At 80-lower.com, we are by no means providing this content on our website to serve as legal advice or legal counsel. We encourage each and every builder to perform their own research around their respective State laws as well as educating themselves on the Federal laws. When performing your own research, please be sure that you are getting your information from a reliable source.