4 Best AR-15 80% Lowers for a Custom Build [2019]

We’ve talked before about what exactly an 80% lower is, and even talked about finishing an 80% lower.  

Today, we’re going to go over the best AR-15 80% or unfinished lowers out there.

tactical machining 80%
Tactical Machining 80% Lower

We’re also going to look at some of the things to be on the lookout for when it comes to choosing an 80% lower.

Note: an 80% lower requires some pretty advanced machining, so the quality, fit, and finish of the final product is going to depend entirely on you, or the person who’s working on it and their skill level.  Disclaimer.

Brief Overview of 80% Lowers

First, should really, really, really, really check out our other article on what exactly is an 80% lower.  

If you’re one of those people too lazy to click links in articles (don’t worry, we’ve all been there) you really just need to know that an 80% is an unfinished lower that is nominally sold as a “paperweight” or other novelty and not a firearm.

If you’re buying a finished AR lower, you’re technically buying a firearm in the eyes of the ATF.

AR-15 80 Receiver Top, ATF
AR-15 80% Lower.  Notice the solid area where the trigger would go, making it a paperweight, not a firearm.  Technically.

Meanwhile, an 80% lower is technically not a firearm until you finish machining it, so you can get them delivered straight to your house without paying FFL fees.  As long as you’re manufacturing the firearm for personal use, and are otherwise allowed to own said firearm in your state, you’re good to go.

Be sure to check out our Gun Laws pages to see if such things are legal where you are.  

Note: California compliance requires a serial number and other changes to your lower, so be super duper sure to check the laws there and in other less-than-gun-friendly states.

To finish your upper, you’ll need an end mill, and a drill or drill press, and a jig or other guide to get you as you mill out the lower.  Each lower is going to require a slightly different procedure so be sure to check with your manufacturer on what you’ll need.  

Drill Through Stock and Buffer Tube
Drill Press

Most of them will have a free pdf or video that’ll show you how to do things.

One thing to keep in mind, even if a company advertises a 90% or 95% finished lower…they still aren’t allowed to get the lower and closer to completion than any other company.  

Measuring the completeness of a part like this is fairly subjective, so just makes sure you don’t pay extra for that ten or fifteen percent and think you’re lessening the amount of work you’ll have to do later.

This is just a marketing tactic and isn’t worth paying more for.  I choose not to buy from companies that advertise that way cause it’s kinda shady…in my opinion.  You’re a responsible (probably) adult.  You’ll have to make that decision for yourself.

What Makes a Good 80% Lower?

There are a few things to consider when choosing your first AR-15 80% lower.  First, tempting as it may be, don’t buy from Uncle Leroy’s Backwoods Firearms.  Small manufacturers are extremely hit or miss, and often lack the precision of a larger, well-known manufacturer.

Aero Precision Lower
If at all possible, try to find someone that you know already makes good lowers, like Aero Precision.

If you’re on your sixth unfinished lower or have the machining background to spot a lower machined to tight tolerances vs one that isn’t, maybe give the small-time outfit a try.  Or maybe you know a competent machinist that can make you one.  Then you’re probably okay, just make sure they have a letter of determination that says they can sell you the thing they’re selling you.

In firearms, as with most things, the “cover your ass” rule is firmly in place.

Second, for your first build make sure you’re getting one that has the appropriate jigs you can purchase, or at least one they recommend you use.  The jig is going to be what lets you finish milling out the lower and making it usable without needing a full-bore CNC machine.

cnc machine parts
With the right tools, you can make all kinds of things though.

Finally, take a look at the materials used.  Polymer lowers are easier to machine, but are more prone to scratching and gouging as well as full-on breakage if you aren’t careful.

Aluminum comes in two flavors, forged and billet.  Basically, the only thing you need to know is that forged aluminum is generally considered to be stronger, but for most people, it isn’t going to matter unless you’re going into combat, and even then it’s not that big of a difference, strength-wise.

Anodized vs Non-Anodized 80% Lowers

One final consideration is the choice between anodized and non-anodized 80% lowers, assuming you’re working with an aluminum lower.  Personally, I would go with a non-anodized lower because you’re going to be milling out large portions of it and exposing non-anodized metal anyway.

Completed AR15 80%
Completed AR15 80% lower, non-anodized

Usually, that means you’re just going to have the thing re-anodized anyway so I’d just go with the cheaper option of the raw aluminum.

Of course, you don’t have to worry about that with polymer as you’re just exposing more of the same polymer as you’re doing your machining.

Best AR-15 80% Lowers

So, here’s our favorite 80% lowers, in no particular order.  These are companies that either we’ve tested, our that have a strong reputation online with other outlets that we also trust.

1. Tactical Machining

Tactical Machining is one of the big dogs when it comes to 80% lowers.  They make awesome AR-15 80%ers, as well as 1911 80% lowers, plus 10/22 80% lowers and even some .308 lowers.

They also make regular finished lowers that require an FFL like a normal firearm purchase.  These guys are on the shortlist for my first 80% build, and I’m excited to give them a try because I’ve heard good things about them from actual machinists who’ve made their own lowers.

Tactical machining 80% lower
Tactical machining 80% lower

Unlike a lot of places, they also seem to have an easier time actually keeping products in stock, and you will probably have an easier time getting a hold of what you want.


What’s more, they also have a number of 80% lower jigs that are perfect for putting together your build.  Trying to drill these things freehand is going to result in scratched and damaged uppers, and probably a great deal of swearing.

Go ahead and get the jig.

Readers' Ratings

4.99/5 (212)

Your Rating?

2. James Madison Tactical

James Madison Tactical makes some excellent AR-15 triggers (If you guys are reading this, I’d love to formally test one) as well polymer AR and .308 lowers.

I also suspect but have been unable to confirm, that they make some of the AR parts kits that get branded and sold with other brand names.  That said, you can also get parts kits from them.

But, we’re here to talk about their lowers.

Personally, I’m not a fan of polymer lowers.  It’s a really stupid hangup I have that’s in no way founded off anything rational.  I own Glocks and other polymer-framed guns…but no polymer framed ARs.  Maybe one day I’ll change that.

If I do, it’ll almost definitely be a James Madison Tactical lower.  I’ve heard nothing but good things from these guys, and I know several 3-Gun and Precision AR shooters that use these lowers.  I’ve shot some of those guns and even competed with one, and I have nothing but nice things to say about it.

Editor's Pick
at Brownells

Prices accurate at time of writing

Prices accurate at time of writing

Their manufacturing process is also really cool.  They use their own polymer-fiber blend with special care taken at common stress points to build a really cool, lightweight lower that is corrosion resistant far beyond what you’ll get with a metal lower.

With a metal lower, you scratch your finish, you immediately have to start worrying about moisture on those parts because you’ll get rust if you’re not careful.

Not so with a polymer lower.  You’ll also not have super visible scratch marks on your lower if you beat it up going through the woods or knocking it around at a competition.

3. Anderson Manufacturing

Anderson Manufacturing is one of the big juggernauts of AR part manufacturers, and they bring that wealth of experience to their lowers.  With these lowers, you’re buying from people who’ve been making AR parts of years, and who sell ridiculous numbers of the things.  

Anderson Arms AR Lower
Anderson Arms AR Lower

There’s a certain comfort in buying from an established, reliable company.  You also get the advantage of availability that smaller shops just can’t give you.  Anderson lowers are available all over the place, and chances are you can find them at a local gun shop, though “local” may be a relative term.

Personally, I’ve built two ARs off Anderson completed lowers, so I can attest to the quality.  These things are rock solid, and in the case of my first competition gun, have been through hell and back with no issues.

Best Value
at Brownells

Prices accurate at time of writing

Prices accurate at time of writing

If you get one of their 80%ers, and you do your part with the machining, I have no doubt that you’ll end up with a reliable, well-done product.

Anderson also has a variety of finishes and designs available so you can be sure you’re getting exactly what you want, which is again something you might not be able to find at a smaller outfit.  

All in all, if you want a straightforward experience with a manufacturer that has a wealth of resources and a large market presence, Anderson might very well be the best option for you.

4. Polymer80

Polymer80 is the other contender for my first polymer lower, especially if I decide to go the 80% route.  These guys and gals specialize in polymer 80% lowers…hence the name.

They also have a freakin’ ton of cool colors available which is perfect if you like to personalize your builds a bit more.

For me, I like building AR’s not just to shoot, but also for the mechanical challenge that comes with this type of thing.  Its really fun to take a box of parts and turn it into a working rifle that you can hunt, compete, and even defend yourself with if need be.

Author's Pick
at Brownells

Prices accurate at time of writing

Prices accurate at time of writing

The cool thing about Polymer80 lowers, besides the awesome colors, is the jig sets you can get with them.

polymer 80 lowers
Pretty colors!

For $80, you can get the lower, the bits you need, and the jig to guide you…basically, everything but you need except for the drill.  

That,  plus a solid afternoon of work will give you a finished AR lower of your very own.  I particularly like the idea of putting together a lower of my very own with this setup.

So much so, that I think I’m going to get one for myself.  Now I just have to decide what color I want.

Parting Shots

There you have it, folks.  These are our favorite 80% lower manufacturers.  If you are looking for a truly rewarding AR build experience without having to pay FFL fees, these are the ones to go with as far as I’m concerned. 

Need to choose other parts to complete your AR-15?  Check out our AR-15 Complete Resource page.

24 Leave a Reply

  • Boxnoiv

    Re the video where the host is interviewing a guy from Brownells: is the host stoned?

    1 second ago
  • Robert Emanuel

    GREAT article - well-explained, BUT - if non-anodized means shiny and not black, how come the weapon in the photo above, identified as "Completed AR15 80% lower, anodized" appears to be NON-anodized?

    3 months ago
    • David, PPT Editor

      Opps, that should read "non-anodized"! Thanks for catching that.

      3 months ago


    4 months ago
    • Blackwallnut

      My thoughts exactly. So now after reading hoping it would get better I know that there is exactly zero value in this article. This article seriously calls into question your bio. Your opinions are worthless in that they are not based on experience with the actual products and processes involved. Are you a poser in all other things?

      2 months ago
  • Brandon Blair

    Has anyone built with juggernaut tactical for a AR10? If so how were they? I am looking to build a quality 6.5 Creedmoor. Any other suggestions would be appreciated.

    4 months ago
  • Aaron

    I'm trying to find an aluminum lower with the features of the juggernaut tactical or the jl billet ones (which i think look great, though i haven't tried them) but WITHOUT the integrated trigger guard.... And obviously, i want it to be a company that isn't some garage operated cnc with a website... If anyone knows of a company producing an 80% lower with threaded takedown pin/ bolt catch's, flared and broached magwells, upper tensioning screws, and an ambi bolt releases, AND with an open trigger guard PLEASE reply. I want to build a high-end AR and i believe that the features i want shouldn't be out of reach because i want to mill it out myself...

    7 months ago
  • Vince Brandt

    5dtactical has got the best one just my opinion

    9 months ago
  • Rob

    Aluminum doesn't rust, so scratching your aluminum lower is not going to lead to rust developing.

    9 months ago
  • Jeffrey Koon

    Only 1 comment/warning - Do Not go to Polymer80!! Have 2 different flavors of their products and neither is properly setup and their jigs are not correct for trigger an/or hammer pin holes. One side on 1 jig was 1/16" off! Closest on 3 jigs is: .009. 2nd, if you clamp their jig onto the 80% and mark out with Sharpie, once you finish machining out FCG you will have a couple problems; 1. cut through on at least 1 side at either trigger or hammer pin region; 2. Opening is not sufficient to properly install trigger/hammer. Also jig piece for trigger hole at bottom is not properly aligned so be gentle. Now onto the main event: A. 556v3 unit - none of the detent holes were drilled and I was not able to find either a 3/32 x 7" or 1/16' x 7" bit to be able to drill out for bolt catch and still have a straight hole. If you follow instructions and jig design, you will have a very, very thin wall or 0 wall for the selector detent. I came up with a solid work around for the takedown/pivot pins and have now even modified my 100% AR to use these. I will try James Madison as I want to have a realistic opportunity to test a polymer lower. I have made many "adjustments" on the Polymer80 products I have and I am now very close to having a G150 finished (ugly but finished) and probably will have the 556v3 finished in another day. I had to use a 1/8" bit to drill for bolt catch and then drill out the bolt catch and make an 1/8" pivot pin and tap the hole to 8-32 and use an allen head set screw. Also, if you take your time, leave more materials than their jig wants, especially at selector detent area, you can use a dremel and gently finish the takedown of materials for trigger, hammer and to make sure detent has plenty of wall. Also be careful of their online PDF instructions (emailed them a month ago now and no changes that I've found) as they leave out important details and they mismark where to and where not to leave materials. Hope this helps you and some of your readers make a more informed decision. I created 2 tickets but only got help with one from Polymer80.

    11 months ago
    • Jack

      I have made 3 Polymer80's, and the worse problem I have found is finding the best tool speed. Another source I know bought a carbide milling bit with great success...far better than the tool steel bits that come with the P80. I am fairly handy with spotting and fixing problems, so I can not argue about the problems you have described, but all 3 of mine are sub moa and completely reliable with no indications of any kind of problems or failure. I did go with a trigger upgrade for each rifle, and am very pleased with them. I have heard real good things about James Madison, and might give one of those a go for a winter project.

      7 months ago
    • Eric Hung

      Dang, I haven't tried P80 for anything besides their glocks which were great. Thanks for sharing your experience.

      11 months ago
  • GMcD

    If you purchase a pre-anodized 80 Lower, does the trigger pocket/milled our area need to be anodized after milling?

    11 months ago
    • David

      Yes and no, if you want complete protection then yes it should be. However, since it is aluminum to start with and that area doesn't really have anything that needs to be protected - it is easy to get away without doing anything to it. Generally, I would at least throw a coat of spray paint down there.

      11 months ago
  • GUNdude

    to make a 80 % to a 100% the best set up is 5d tactical I know this was about the best 80% lowers but this is the easiest way to get it done and I drop the mic and walk away

    1 year ago
  • Stephen

    Uh, if you buy something that is more than 80% finished, you are buying a firearm. Also, if you have your machinist friend finish an 80% for you and you take possession, you are both in a heap of trouble.

    1 year ago
  • Mjd

    Jl billet best 80% aluminum lower James Madison best 80% polymer lower Both offer AR10 and AR15 My 2 cents

    1 year ago
  • Jake

    Tennessee Arms Co. has an excellent looking lineup of 80% and complete polymer lowers. They've got a threaded brass insert for the buffer tube which takes care of my main worry with poly lowers. I just ordered mine! Should be able to have it all milled out by Christmas.

    1 year ago
  • Wzrd

    Since I’m already milling/routing I like to add PDQ levers to mine. Not cheap compared to standard bolt catch but gives you ambi bolt catch/release.

    1 year ago
  • Jim M.

    I've used 80%arms Gen I jig and 80%arms billeted lower. I love them! FYI, use masking tape and tape a shopvac to the threaded buffer tube port while milling. Thank me later;)

    1 year ago
  • Wzrd

    Never used one but 80percentarms has nice looking billet lowers in AR15 & AR308. I used their new Easy Jig Gen 2 & a router to do my 80%s. Also can get New Frontier Armory style AR9 & AR45 80% lowers now. I have one of each laying around waiting to be built over the winter. The Easy Jig Gen 2 can supposedly do them all. Another cool looking billet 80% maker is Juggernaut Tactical. They offer their lowers with ambi bolt release.

    1 year ago
    • Eric Hung

      Yup, looking to get my hands on an Easy Jig Gen 2 in the new year!

      1 year ago
  • Rhod

    Interesting you didn’t mention Juggernaut Tactical. Their 80% is loaded with features and are billet, so they’re nice to look at too.

    1 year ago
    • Eric Hung

      Hmm, haven't heard of them yet, thanks for the rec.

      1 year ago
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