Although many of you are already well-versed with the AR-15, there are many new firearm enthusiasts that are entering the market every day.
Because of the popularity of the AR, almost everybody wants to get at least one. When deciding on your first AR-15, there are a couple of key things you will want to consider before making your purchase.
Let’s take a look at what you want to look for when buying your first AR-15.
Build Type: Fully Assembled, Partially Assembled or From Scratch
There are three main AR-15 build styles:
- You can buy a complete rifle.
- You can piece together completed upper and lower receivers.
- You can do a complete build from scratch.
For your first AR, I would suggest selecting a good-quality complete rifle from a reputable manufacturer. This tends to lead to a more reliable firearm, especially if you don’t have experience building an AR-15.
If you don’t find a complete rifle that you like, then you may want to consider purchasing a complete upper and lower receiver assembly. That is much easier to piece together—just two pins—and can still lead to a reliable rifle.
This allows you to make sure your complete firearm has all the features you want if you cannot find them on a factory-built rifle.
Classification: Commercial or Mil-Spec
Commercial or Mil-Spec? This will determine the buffer tubes and stocks you are able to use. The two need to match—Mil-Spec with Mil-Spec and commercial with commercial.
With modern-day components, there is not really much of a difference in quality and availability, but most shooters tend to prefer Mil-Spec.
Mil-Spec was the original, but companies realized they could produce the tubes cheaper by making the tube slightly larger in diameter (0.02-inch) and cut the threads in, as opposed to Mil-Spec where threads are rolled in.
There is no evidence to suggest that either option is stronger or more durable.
Operation: Direct Impingement or Gas Piston
Piston is more expensive, but it is thought to be a lot cleaner on internal parts, though I have had no problem with my direct-impingement firearms.
Direct impingement is a simpler mechanism with less to go wrong. In a direct-impingement firearm, the gas is directed up into the gas tube and forced back into the gas key.
This force pushes the bolt carrier group back and operates the semi-automatic action. In a gas piston firearm, when gas forces reach the gas block, they stop and hit a solid piston.
The piston then cycles back and forces the bolt carrier group back and operates the semi-automatic action.
The piston traps most of the carbon build-up and keeps the rest of the rifle cleaner, making it easier to clean and theoretically able to run longer between cleanings.
Receivers: Forged, Billet or Cast
Most AR receivers are made out of heat-treated aluminum and are either forged or billet. Cast receivers exist, but they are scarce and not typically great. Receivers are either constructed of 6061 or 7075 aluminum.
- 6061 tends to be less expensive and durable, but is also more corrosion resistant.
- 7075 is a stronger material and more costly, but tends to stand up to abuse a little bit better.
Forged receivers are made by hammering two roughly shaped halves together, then cleaning them up later with machines. This method is quicker and cheaper to produce and still leads to a quality rifle.
Billet receivers are made by taking a single block of aluminum and a CNC machine milling out the lower. This method takes longer and is more expensive but allows for more unique designs and patterns.
Hammer-hardened forging tend to make the lower more durable and they are lighter weight because of less excess material, but with modern materials, a good 7075 billet lower is basically just as strong.
There are also polymer receivers, which have come a long way in past years. However, my suggestion would be to stay away from polymer lowers because they tend to have issues.
Unless you’re going for an extremely light-weight build, they are not the best choice, especially for your first AR-15.
Parts and Accessories
You will also want to take a look at the style of gas block used in the rifle. Many starter AR-15s are equipped with a standard A2 front sight post and gas block.
This is a solid starter option, especially if you only intend to use iron sights. If you want to install a free-float handguard, you will need to have a low-profile gas block.
This is easy enough to install later on if you choose. If the rifle or upper receiver you are looking at already has a free-float handguard, it will already have the low-profile gas block installed.
One final consideration to make would be an adjustable gas block. These are typically not recommended for defensive use because they can sometimes affect reliability, but they are great for competition.
Adjustable gas blocks allow the user to regulate the amount of gas pressure sent back to the bolt for different ammunition loadings.
They are also great for suppressor use because you can adjust the gas pressure to make sure your rifle functions properly.
Many budget rifles do not come with iron sights. This is a cost-saving measure on the part of the company, as they assume most users will want to install their preferred sights or optics anyway.
If they are not included, however, you will want to factor this into the overall cost, as your AR-15 will be virtually useless at any range without a sighting system.
If you are looking for basic sights for your first AR, Magpul makes a quality set of both polymer and metal flip-up sights that can be had at an affordable price.
Most ARs will come with at least one magazine, though I have seen some that don’t.
Make sure to check on this when you do decide to purchase, and you may want to consider grabbing some additional mags for an easier time at the range.
Magpul P-Mags have basically become the industry standard, and have even made their way into military service. They are incredibly affordable and reliable.
P-Mags can be found for incredibly low prices, usually between $12-20 a piece, depending on the generation and whether you would like clear window cutouts to quickly view your remaining ammunition capacity.
How many magazines do you need? This is entirely personal preference and dependant on what you purchased your AR-15 for. However, I personally like to keep around 10 magazines per rifle.
You do not need to gather theses all at once, you can add to your collection as your budget allows, spending another $15 here and there. (Read a review of the above UTG AR-15 mag here.)
There are tons of options for handguards for the AR-15. Most budget rifles will include a standard GI style, plastic two-piece system.
This is an OK start, especially if you don’t plan on firing the rifle much, but it certainly is not the best option. These typically don’t contain a heat shield and can easily crack if dropped.
They also allow for the attachment of rail sections so you can mount forward grips, lights and lasers.
If, however, you want the full tactical look, you may want to consider finding an AR with a free-float rail (either KeyMod or M-LOK). This can be added on later as well, but it is more difficult.
This can not only aid in improving accuracy in the hands of experienced marksman but allows for a multitude of attachment points for your various gadgets.
Deciding between M-LOK and KeyMod is mostly up to user preference. Both allow for more space on the rifle to place your hand and attach accessories, the difference is only in the method of attachment.
Most people turn to M-LOK because it is more secure.
But KeyMod will most likely serve you just fine and these handguards are often discounted, though only time will tell whether parts availability with KeyMod will begin to die down.
One final consideration is the quad rail handguard.
The modern tactical community typically considers these outdated because they add unnecessary weight, but they are perfectly functional and offer quite a lot of attachment space.
These can be found in either two-piece systems as well as free-float versions.
Choosing a stock is largely dependent on personal preference. Most are collapsible, six-position variants (if that is legal in your state).
However, you can also find fixed stocks and attachments to make folding stocks.
One important thing to remember is that you must have, at minimum, a 16-inch barrel to attach a stock without filling out required ATF paperwork to file for a short-barreled rifle.
We’ll touch more on this later, but for now, just keep that in mind. Most stocks will feel very similar when pressed up against your shoulder and will perform the same basic function.
Most entry-level AR-15s will come with a standard single-stage trigger. A single-stage trigger has very little, if any, take-up and has a nice, crisp break right as you pull.
This is a good starting point for most users and is great for quick follow-up shots, but tends to not be as conducive for accuracy at long ranges as a two-stage trigger.
A two-stage trigger has some travel before the break, referred to as “slack” and then reaches the crisp break.
This allows you to stage the trigger until the breaking point, and can then complete the travel when you find your perfect shot.
Depending on what you want to use your AR for, finding a rifle with a reputable two-stage trigger may be preferable. Deciding on a single-stage or two-stage trigger is personal preference.
Some like the security of having some slack in the trigger before the break—whether that be for accuracy purposes or a sort of safety in a defensive scenario—and therefore lean towards two-stage triggers.
Others prefer the quick, crisp break of a single-stage trigger. My suggestion is to try out each at your local range or gun store and decide for yourself.
Staking the gas key keeps it properly attached to the bolt carrier through the extreme force the gas exhibits on the unit. The point of staking the gas key is to keep the screws from working loose.
This is due to the frequent back and forth movement by adding extra friction, while still allowing the removal, if necessary for maintenance or replacement, through extreme force.
If the gas key comes loose, it can cause malfunctions and your AR-15 to not operate correctly.
There’s a lot of debate about this one, but you may want to consider finding a rifle with a staked castle nut or staking it yourself. The reason for this is that staking makes sure your castle nut doesn’t come loose.
The castle nut holds your buffer tube assembly to the AR-15 lower receiver, if this works itself loose it can cause issues in reliability and durability of the firearm.
Most castle nuts will have a notch included where you will be able to stake them down. This action is typically considered permanent, but you can remove it if you need to with an armorer’s wrench.
Other options include applying a small amount of Loctite on the threads or simply to torque down the castle nut and hope for the best.
Size/Barrel Length: AR Pistol or Rifle/Carbine
Finally, you will want to decide on the size and barrel length of your AR-15. Most first-time buyers select a 16″ “carbine-length” platform, but that is not to say that it is for everyone.
The emerging trend is to get short-barreled ARs, which are classified as pistols until you decide on filling out the proper ATF paperwork, attaching a true stock and making it a short-barreled rifle.
It is important to remember that you can go from a registered pistol to rifle, but not vice-versa. A 16″ barrel is as low as you can go with a firearm that is legally defined as a rifle; anything shorter will be considered a pistol.
An 18″ barrel is considered “mid-length” and anything above is called “rifle-length.”
All lengths have their benefits. The shorter you go, the more maneuverable and lightweight the firearm is, while longer barrels have higher ballistic performance and longer range capabilities.
Decide on what you want to use your AR-15 for and then select the barrel length that best fits your application.
Whatever AR-15 you decide on, make sure you are happy with it. Don’t go out of your way to buy the firearm other people think you need.
ARs are like the LEGOs of the firearms world. If you want to add or change features later, you can always do so on your own time.
Just make sure you take the time to know what you are looking at before you buy so you don’t regret your decision later.
What was your first AR-15? Which style did you choose? Let us know in the comments below!