When I told friends and family that I would be building an AR for the first time, it was pretty much only my father who asked me if I knew how to ensure the thing didn't blow up in my face. Once I explained that I did know and what it entailed, he didn't have any other questions. I build computers, fences, furniture, and many other things myself - because I want them made a certain way. So, aside from my dad, no one asked me if I knew what I was doing. They assumed I did. No one asked me if I really wanted to. They knew I did.
But, do you really want to?
There are a ton of things to know, some more important than others, like the specs for how tight to torque the barrel nut (Min 30 ft-lbs; Max 80 ft-lbs), for instance. But, it's more than knowing specifications. You have to choose parts, which means you need to know what parts you need and which particular design is best. For instance, which handguard/rail and which gas block do you want? Perhaps, even more importantly, are they compatible with each other? Are they compatible with the barrel you've chosen? There really are a ton of things to know.
That said, I found it to be extremely rewarding. During the process, I learned so much about my guns. I learned how important staking a Castle Nut is and why. I learned the differences in materials and which is actually better. I learned how the gas and buffer system relate to one another. And, more than any of that, I know there are no cut corners on my gun. Everything is just as I prefer it - and that is what really makes it all worth it. At least to me. As the old adage goes: if you want it done right, do it yourself.
Here are the top 10 things, in my opinion, for you to consider before going down the path of building an AR:
- Is it worth it to you to buy the proper tools? You need a bench, a bench-vise, a Castle Nut tool, a Torque Wrench, Vise Blocks, numerous Star and Allen bits, pin punches, a good hammer, and some heavy-duty grease. If you'll only build one, that's a lot of expense for just one rifle.
- Do you know enough of the parts and how they fit together to be able to purchase them all and fit them together? You can buy parts kits and watch Youtube videos, but it will take hours to digest all the info you need.
- Do you know what you want from your gun or how each material or design effects the performance of the gun? Hint: the internet is full of clowns with no clue who speak from ignorance, simply parroting what they read on another forum.
- Do you have a place to put a work bench and these extra tools or a place you can work on them without getting noise complaints from the apartment above you? Having a place to essentially build a work area is important.
- What are the applicable State and Federal laws about what are permitted features of the gun? This is extremely important for our Comrades in California. Anywhere on the Left Coast, actually, and places like Chicago and Washington DC.
- Are you building it to do it cheaper? You should comparison shop before trying to save money by building it yourself. Aero Precision will be tough to beat on price for their pre-built rifle with no furniture, exclusively at Brownells.
- Are you just doing it to learn about your rifle? This is no doubt the best way to learn about your rifle, but it can be the school of hard knocks.
- Are you mechanically inclined enough to understand how these parts fit together? A lot of guys do not know how to properly torque things and they have serious malfunctions because of the weird ways some guys install their triggers, to name a couple common issues.
- Is there a gunsmith you know that you can go to if you get stuck and need help? This is key. As long as you have this for a back-up plan, all the money you've invested in the project will likely not go to waste.
- Are you going to purchase go/no-go gauges to ensure headspacing? If not, or if you don't know how to use them, I urge you to consider paying a qualified gunsmith to check the headspace and even test fire it before you take it on the range and try it yourself. (Or, buy a factory-built upper and build your own lower to avoid that issue.)
- Barrels - What type of barrel do I need? There are 3 uses I can Identify for a barrel: combat, distance shooting, and competition shooting.
- Combat - If you want to defend yourself with this gun, anywhere from 0-300 yards, I would recommend a Cold Hammer Forged barrel with chrome lining, chambered in 5.56 or .223 Wylde. (You won't find such a barrel in wylde atm. Criterion is the closest thing to offering that.) Why Chrome? Man has not yet devised a way to make a barrel more durable for rapid fire than to Chrome-line it. Melonite is fine, but it will wear down much faster than Chrome, because the nitriding just doesn't penetrate that deep into the metal, and you probably wouldn't want it to. It would make the surface very hard, but the barrel itself would shatter more easily if the barrel was melonited throughout the material. Why Cold Hammer Forge? It increases the sectional density of the metal. It also ensures consistent rifling from one barrel to the next. If you find a Cold Hammer Forged barrel you really like, you can get a nearly identical rifling on the other barrels being produced by that company.
- Competition Shooting - This is simple. You want stainless steel for this. Why? Predictable rate of wear and the most precise rifling. You can melonite it, but that can throw off point of impact. Since you might be lugging it all of 40 feet, it's acceptable to get a heavy bull barrel. Basically, whatever improves accuracy and consistency.
- Hunting/Outdoors - This is where melonite shines, in my opinion. Your rifle will be exposed to the elements, at night in many cases, and you probably aren't going full auto on a deer or any 400 yard target. For corrosion resistance and general durability, melonite is an outstanding choice. Stainless isn't bad here and neither is a chrome-lined barrel, but stainless Is less durable and more visible, while a chromed barrel doesn't have the resistance to the elements on the outer surface that a fully melonited barrel has. When stealth matters, particularly in low-light conditions, melonite's black color will be great.
- Forged or Billet - Which is right for you?
- Forged is my preference, mostly due to cost. I do like Billet because it can be made lighter than forged by taking off less-needed metal and any machine shop can potentially make it, which makes it real hard for the government or a terrorist to shut down that part of the industry. (What happens if someone shuts down the 12, or so, forges and cut off the supply of AR15s? Both military and civilian, potentially.) Either will work well. I only caution you to be careful with the weight of a Billet Receiver - sometimes, they can be way too heavy or the weight-savings can be too aggressive and you really don't want the receiver walls to fail. Typical forged receiver weights are a good baseline - about 10 ounces for an upper. Don't vary much from that and you should be ok. (The lower handles significantly less stress and will generally be fine, structurally.)
- Match Triggers - Do I need one and are they worth it?
- No, no one needs a match trigger, but it sure helps for competition shooting and distance shooting. I would recommend a drop-in, single-stage trigger like a CMC or Wilson, assuming this is meant to defend life and liberty. For competition, I've heard great things about AR-Gold triggers and I know Geissele makes great triggers, as well. If you don't want to shell out $250+ for a decent trigger that pulls crisply and is ultra-reliable, I highly recommend ALG's QMS trigger. Nothing will be more reliable in your rifle than the "mil-spec" triggers, but a few competition versions can match that reliability with added benefit. I typically go mil-spec, unless the rifle is purpose-built for distance shooting.
- Brands - What brand should I choose for parts?
- Well, some brands make great rifles, but getting their stripped receivers are a real problem, such as with Daniel Defense. My advice is to get Wilson Combat (Forged), Aero Precision, or Spike's Tactical - any of those are great, they're easy to find online, and you should be very happy with the quality, especially Wilson Combat. Any reputable company should be perfectly fine, especially if it's forged. For other parts, I generally stick to BCM, Spike's, ODIN Works, Daniel Defense, Mission First Tactical, and V-Seven. For specific recommendations, check my Builder's List for my favorites. I stay away from some brands due to reputation or my personal experience, but I don't want to call them out by name.
- Length of Barrel - What length should I get?
- To me, its not worth paying $200 and waiting several months, on top of having an attorney draft a trust for you to get a barrel below 16". Now, if you want to get a 14.5" barrel and have the muzzle device affixed to it permanently, that's a way around the unconstitutional NFA rules. But, that reduces the velocity of the round (due to the shorter length), you're probably having to pay someone to do that for you to ensure it satisfies the law, and you're probably not going to be able to re-use the muzzle device on a new barrel. Anything less than 16" is really just extra money for no real improvement in performance. That said, I would only go above 16" if you were building this rifle for distances beyond 300 yards, in which case I recommend either an 18" or 20" barrel. Any longer than that is not practical if you need to use it in a typical US building code hallway. (As in a home-defense situation.)
- But, what if there were no NFA? (Or, if I were willing to pay the money and wait.) If there were no NFA, I would probably have a 10.5" barrel with a suppressor on my bedside gun, but definitely no shorter. Barrels below 10.5" are prone to reliability issues because, in many cases, it just doesn't get enough gas to properly cycle the weapon before the bullet exits the barrel and it doesn't load the next round or has problems loading the next round. (Also known as a "dwell time" issue.)