Build an AR-15: Step by Step–Series Introduction

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I'm 6'4", and have issues with short rifles. My first attempts at building an AR were designed to build a gun that fit my height.

I’m 6’4″, and have issues with short rifles. My first attempts at building an AR were designed to build a gun that fit my height.

Most of us who own AR-15s buy rifles off the shelf. That shouldn’t be a surprise. There are more than 200 companies making ARs today. With the vast array of available models, most shooters can typically find a rifle that fits all of his or her needs.

But I have yet to meet anyone who is serious about black rifles who hasn’t at least expressed a desire to build an AR from scratch. You don’t need to be a gunsmith. You don’t even have to be all-that-handy. The parts are designed around the concept of modularity, which means you can put them together like you would a model airplane–only with less messy glue. I asked a friend who has built guns about the experience and he swers its so easy that he could teach a seven year old to do it.

But why would you want to? And what will you need to do it? GunsAmerica News and Reviews will be covering it all in the coming weeks. This will be the first in a series of articles that will take the build process from the ground up, and today we’re looking at the first in what will be a long list of important concepts.

Why build your own AR?

Cost: Some are looking for an economical way to build a rifle. This makes sense. If you don’t have enough money to buy a complete rifle, but have the patience to spend smaller amounts over a longer time, you can end up with a complete gun. But beware–it will likely cost you more to build your own. You may not have to pony up all at once, but you will likely spend more over the long haul.

Why is that? Rifle companies build their own parts or buy in bulk. Think quantity discounts. Even when you see shockingly low prices on some parts from a retailer (like a striped lower that’s a steal), you will find that the other parts may not be such a bargain.

Still–I know this lay-away strategy all too well. I’m not going to admit to being deceitful, but I will say that someone significant may notice the sudden dent that a nice AR is going to put in your shared bank account. But if you spread those costs out over time, then you don’t draw so much attention to the purchase, and you have something to tinker with in the meantime.

If you’re just looking for an entry level rifle, though, the build-your-own, do-it-yourself approach may be ludicrous. Click on the link below to see exactly what I mean.

Buy a Complete AR-15 on GunsAmerica: /AR-15

You can monkey with your rifle by rebuilding it with new parts, or you can by all new parts and build from the ground up.

You can monkey with an existing rifle by rebuilding it with new parts, or you can by all new parts and build from the ground up. Either way, you should be able to build a rifle that does exactly what you want it to.

Customization: There are very few guns that can be customized in half the number of ways the AR can. The 1911 comes to mind. The Remington 870, maybe. But the AR is really its own animal. This may seem odd when you think about the rifle’s origins. Rifles issued to armies are usually very similar. They are supposed to be exactly the same; it makes maintaining the guns, and training with them much easier. In the civilian world, though, we use the AR’s modularity to fit parts that fit us. And we change everything. EVERYTHING.

Bigger, better, longer, thinner, lighter–each of us have different needs, and the AR can be tailored to fit those needs. Need a long range rifle? The AR can do that. Want one that weighs 6 pounds? No problem. Need something that will fold up to fit in a briefcase? You see where this is going.

Once you get a handle on the basics, you may want to mill your own lower. We're building one now.

Once you get a handle on the basics, you may want to mill your own lower. We’re building one now.

Expertise: With so many models and variants available, most of which are priced competitively, can’t you just find one off the shelf that meets your needs? Usually. But you would be giving up the experience you gain from doing the assembly yourself. What will you do when you are in the field and your rifle stops working? First you have to diagnose what’s wrong. Then you have to fix it. If you’re lucky enough to have built a rifle from the ground up, and you have a few common parts and tools on hand, you will likely be able to fix the problem.

We’re going to break it down. And while we’re putting together this series, we’re going to be building a couple of rifles.

How to Build an AR-15:

  • Build an AR–Caliber Selection–The first piece of our new series is already up. 5.56 is just the start. From .22 LR to .416 Hushpuppy and beyond. Anything is possible with the AR platform. We’ll cover the popular, and the obscure. You have to know what you want your rifle to do, and a lot of what it can (or can’t) do depends on the caliber.
  • Build an AR–Gas vs. Piston–It is a basic decision, but it shapes the way the rifle is going to work. Do you go with the tried and true (and often dirty) gas system, or do you pick the long term benefits of a piston system? We’ll break them down and discuss the strengths and weaknesses of each.
  • Build an AR–Tools and Materials–What do you need to build an AR? We’ll put together a list of the tools and various parts. While you won’t need them all at once, it is a good idea to see what you’re getting into before you get started–and after making the decisions about caliber, and deciding on gas or piston, you’ll be ready to build a functional list of materials and tools.
  • Build an AR–The Low Down on Lowers–The lower is the serialized part on these guns, and there are a lot of options. As the centerpiece of the platform it is a defining feature. We’ll look at the various options.
  • Build an AR–Uppers–It is hard to make uppers sexy, but they matter. Uppers hold most of the moving parts, and take a tremendous beating. They don’t get the attention they deserve, and we’re out to remedy that.
  • Build an AR–Barrels–While the rest of the rifle is undoubtedly important, nothing makes or breaks a good AR like a quality barrel. And there are some subtle differences that we’ll explore in depth.
  • Build an AR–Forends--Most of us like having something to hold onto while when the gun goes off, and the forend provides a convenient hand hold. They also shield heat and can provide extra real estate for mounting accessories. Well look at the various designs and offer up our opinions on what works, and why.
  • Build an AR–Stocks and Grips–From minimalist designs and folding stocks, to adjustable stocks meant for a perfect fit, we’ve tried them. We’ll talk about design, purpose, and function of grips and stocks and how they break out into recognizable groups.
  • Build an AR– Choosing the Right Optic — When deciding on the perfect optic for your AR build, the very first thing you need to do is match the performance window of the optic with the performance window of your rifle. For example, installing an optic that’s optimized for 1,500-yard shooting won’t do a whole lot of good on a Cricket .22LR bolt-action youth rifle. While that’s an exaggeration, the concept of matching performance characteristics does come into play with the AR family.
  • Build an AR–Enhanced Controls–There’s a lot to cover in this section. We’ll be looking at everything from Mil-spec triggers to over-sized charging handles. If you’re new to AR customization, get ready–this is one of the more expensive segments we’ll examine.
  • Build an AR–Magazines–AR mags are not as finicky as the mags of other platforms, but they’re still important. If they’re unreliable, the rifle won’t work. You don’t want to invest time and money in a rifle only to have it lock when you feed it.
  • Build an AR–Extras–one reason why the AR has stood the test of time is because of the exhaustive variety of accessories that you can stick on a gun. We’ll look at the practical approaches (like lights and foregrips), and some of the whacky alternatives (like knives and other guns).
  • Build an AR–Final Assembly–I’ve been told that assembling an AR is about as easy as making a peanut-butter and jelly sandwich. I can screw that up, so I’m bound to run into some problems. What should you watch for when you put everything together? And how do you test out your new rifle–safely and thoroughly?
Know ahead of time that it is highly unlikely that you'll save any money by building most rifles yourself. Manufacturers buy parts in volume, and see low margins on each sale.

Know ahead of time that it is highly unlikely that you’ll save any money by building most rifles yourself. Manufacturers buy parts in volume, and see low margins on each sale.

So Stay Tuned

Along the way, we’ll be compiling a running list of resources. We’ll talk in depth about manufacturers, retailers

I’m going to come clean about something. I’ve been slow to accept the relative dominance of the AR-15. I’m an AK devotee. I own several ARs, but I’ve come by all of them rather casually. As the Editor of GunsAmerica’s News and Reviews, I often find that I need an AR on hand. And I’m going to be building a rifle, too. For me, it is that last category that motivates me: expertise. It is time to stop sitting idly by, watching others build guns. Time to get my hands dirty. So I’m going to be building a gun as we go along. And if it can be done by a seven year old, I have one of those, too. Maybe we’ll test that theory and have him put down the Legos long enough to build a rifle.

More from this Series:

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{ 24 comments… add one }
  • Alex Escott July 10, 2016, 8:53 am

    Was this series ever finished? All I can find is the series introduction, and gas vs. Piston. If not can anyone suggest another source? Thanks

  • Matt October 31, 2015, 10:52 am

    What happened to the rest of this series ? I really was enjoying it.

  • David G. July 27, 2015, 9:55 am

    I disagree with the notion that you pay more for a build it yourself AR15. I’m currently building a new rifle and have “patiently waited” for “high quality” parts to come on sale. I’m waiting now on my barrel, adjustable gas block and I’ll have a finished rifle after being a careful shopper for the last 8 months and will have a $1500.00 rifle value for just a little under $800.00. Can’t argue with that…..

  • Dave July 9, 2015, 11:24 pm

    I have built quite a few bolt rifles on Mauser and Rem700 receivers. After your article a few weeks ago about 80% “ghost gun” receivers, I have acquired an urge to build an AR rifle in 7.62 NATO. From what little shopping I’ve done so far, the uppers look pricey and scarce. Please pass on any deals you run across!

  • Mark July 7, 2015, 8:08 am

    I’ve always been intrigued with the caliber of my first deer rifle, 35 Remington. Rimless case and heavy bullets along with .357 bullets made for what I thought was a versatile woods gun. With the advent of the polymer tip bullets for the Hornady revolution (sic) rounds for lever guns, my thought is that it opens up even more ballistics. I write this not knowing if the current chamberings in this article make my thoughts redundant. I am just nostalgic over the 35 Remington. Maybe that’s enough reason in itself. Time to take some notes. Always thought a 35 Remington “mini 35” would be a great gun as well.

    • Carl E. Churchill July 7, 2015, 2:59 pm

      I too am a 35 REM owner and I love the rifle. I recently had the barrel and receiver assembly completely rebuilt and blued by a gunsmith friend of mine. I made the mistake of loaning the rifle to a friend who had left it out in his garage (although in a soft case) it rusted quite badly and the wood components dried up severely. He happened to live on the coast and the salt air did all the damage. I personally redid the forearm and the stock wood components by hand and brought them back to a nice luster. The total cost of rebuilding the barrel and receiver assemblies was $200 and I put another $30 in materials to complete the stock. Now I have my original 35 REM back in operating order and it looks relatively new except for a few very small areas where the rust etched into the metal…now we call that PATINA! It’s still a great brush rifle.

  • 5WarVeteran July 6, 2015, 7:15 pm

    I finished my first build last week. It was a specific build of PSA AR-9. A black rifle camo’ed with Viet Nam Tiger Stripe Camo. Looks really great. The point of this weapon was low cost ammo that will use the same 9mm rounds in my CCWs. Good for 100 yards is plenty enough with a 1/10 twist.
    It is exactly what I wanted….

  • DRAINO July 2, 2015, 8:14 am

    Why build an AR? Why Reload? Why do your own car repairs? Why do your own home repairs? Why do anything yourself? Why paint a picture? Why create a sculpture or pottery? Why create a website or build your own computer?
    Because its AMERICA! And we CAN!!! It’s called Freedom. A rare thing these days. Exercise your freedom…or you may loose it.

  • michael June 30, 2015, 9:31 pm

    i just finished my build a retro m16 .took me three months or so buying as i went along…it looks awesome i had some much fun doing research learning the history of the rifle etc. my wife cant believe it.”it looks cool when can i shoot it” ye3a it was worth it.i already started a second……..

    • Ron April 12, 2017, 1:45 am

      Which version M-16 did u build? What would u think of an A2 with 10″ barrel pistol?

  • Gene June 30, 2015, 11:27 am

    I just completed my first build and built an A2 style rifle. It was very fun and easy. I took it to my gunsmith upon completion to have him inspect and check the head space for safety. It was all good. I really recommend building one from parts to learn how simple the rifle really is and to truly understand how it works. Look for parts on sale and stock up on them for future builds. I have bought stripped lowers for as low as $39 each. Very satisfying to build it yourself. Starting a .308 soon.

  • Joe W June 30, 2015, 12:15 am

    I was able to build a 300 AAC Blackout for $1025 16″ complete diamond fluted stainless steel upper from Red Xarms $350, CMC 2 stage drop in trigger $200, Palmetto State Armory lower kit charging handle and nickel boron coated BCG $195 and Anderson lower for $80. Vortex strikeforce red dot sight and ultimate arms pop-up iron sights.

  • Bob Lawman June 29, 2015, 11:52 am

    David, as a minor league Gunsmith (only because I am limited to not affording the machines to do the machining of everything) and as an old school AR-15 shooter and builder, I say ABOUT TIME.. for you to build your own. You have progressed well in your knowledge and proficiency in the gun world since the last time we actually were face to face talking. I admire your adventure and your enthusiasm. I know you will do well and will assemble and complete an original unique to your statue and your taste buds. Good luck to you but I know you will prevail very well. I have complete faith in you!!

  • Joe June 29, 2015, 11:13 am

    After getting done personalizing my carbine which jumped the investment to 1300 bucks, the thought of starting a new build from scratch scares the hell out of my budget….SOooo. Maybe an eighty percent lower to start, then…who knows.

  • Mahatma Muhjesbude June 29, 2015, 11:09 am

    Great series idea, Paul. You are a great American patriot by helping to keep the world’s largest standing army well equipped and trained! Plus you are helping to stimulate the economy. Building AR’s and even other ‘HO-made’ firearms can become a cottage industry the likes of those which once made our Great Nation a bastion of free enterprise.

    Make sure you guys check out the latest evolution of the military combat AR-15 contract(i think Danial Defense has the contract)–, as sort of a base line of build parameters, the new M-18.(SOPMOD) Supposedly just for spec-ops people, i guarantee it will wind up being the standard infantry carry issue in the future, with maybe a little longer barrel. Especially when they eventually come out with the new tweaked 5.56 combat ammo they were considering before budget constraints killed the upgrade. No more carry handle or elevated front sight gas block. about time. it reminds me of the original CAR-15 which was the best all around weapon i ever carried in combat.

  • Jeff June 29, 2015, 9:43 am

    It actually isn’t entirely true that it is more expensive to build one yourself. If you are comparing an entry level AR to an entry level build yes that statement is most likely true. However in my experience I have built a few AR’s and when you use parts that are considered aftermarket the savings can add up, especially when you source parts from different retailers during their sales. For example one of my builds contains a midlength barrel in 1:8 twist (which is rare to find over-the-counter) non standard flash hider, bcm grip, magpul buttstock, magpul handguard, nitride coated bolt carrier, bcm charging handle, pop-up iron-sights, plus a standard lower and upper and all other internal parts for under $500 which would cost over-the-counter over $800. So building an AR has its benefits when considering building an AR that suits your needs. Not to mention you well know exactly how the rifle goes together and how to fix it if something goes wrong with it.

  • WillB June 29, 2015, 9:17 am

    Had a Colt AR15 years ago but got rid of it since it was illegal to use for hunting in my State (then). Have a HK and liked it better since it does not need a buffer or a forward assist.

    But now I am building an AR just for the fun of it. Have not picked a caliber yet, just got the billet upper and lower receivers (no forward assist). Look forward to your articles since I plan to take my time building the rifle (and buying the parts).

  • Jim June 29, 2015, 8:16 am

    One advantage to building your own is that you can come up with a platform that is difficult to find any other way, such as a retro AR15. I’ve built an semi-auto version of the M16A1 that looks like the one I carried back in ’69, and have the upper assembled for an XM177E1, though I went ahead and used a pinned barrel to avoid having to get a stamp. Besides that, building ’em is just plain fun!

  • Greg June 29, 2015, 7:20 am

    After noticing I had about 1/3 of a rifle after I did all of the upgrades on mine, I offered my 16 yr old son a deal–if he put it together (under my supervision) the new rifle would be his to use. It was a great learning experience for both of us–we took our time, watched lots of videos and replaced lots of springs. In the end, we had a great performing rifle that he was very proud of. We both really enjoyed doing that.
    Anderson upper/lower/bolt
    Stoner SOCOM Profile Barrel
    MAGPUL Stock and Grip
    Geissle SSG trigger
    Diamondhead forearm
    Burris MTAC

  • Tommy T. June 29, 2015, 6:53 am

    Is one of the benefits of an AR-15 being modular the fact that you can have two or more uppers for different purposes? Using just one lower while selecting an upper for the occasion makes a “collection” cheaper and easier to build.

    • Administrator June 29, 2015, 6:57 am

      Yea, that is the idea of creating new calibers that will fit into an AR magwell and that use the .223 cartridge bolt face. Overall you get to experiment with different calibers using as many common parts as possible.

    • Cody M. June 29, 2015, 1:16 pm

      Yes, you can buy a ready to shoot upper for around 300 bucks with everything but optics. I have a cqb upper (close range jargon) on for home defense and a long range upper with an already zeroed optic waiting for fun at the range or shtf.
      I am a new and happy customer with CDNN Sports, they sell uppers with rails for close to msrp on the rails alone. Check around at a few places for good ideas on prices.
      If you buy a second upper your long range doesn’t need quick release optics mounts, save yourself the extra ounces, IMHO.
      If you happen to be new to the platform you can get an upper off with a bullet in a pinch (Two pins), just be gentle so you don’t mar your pins too bad. A totally black rifle is an unused rifle, though, so no one will look down on you for normal wear signs unless they are mall ninjas.
      Hope that helps.

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