The Ultimate AR-15 Guide

It is no secret that the AR-15 is the most popular rifle in America, and that gives your average gun owner plenty of options to choose from when it

comes to buying one. Here we are going to cover everything AR-15 related, and help you not only come to know the AR-15 better, but maybe find the perfect rifle for you!

AR-15 Rifle

Table of Contents

Why Choose an AR-15?
History of the AR-15
Building or Buying
AR-15 Parts
Bolt Carrier Groups
Triggers, Handguards, and More
High-Quality AR-15 Manufacturers
The Best AR-15 Rifles

Why Choose an AR-15?

Like we said before, the AR-15 is this country’s favorite rifle. It might even be in a close run for the overall favorite rifle in the entire world. There are many reasons for this, like:

1. It’s used by the United States Military

Ok, technically the military uses the M16 or M4, which the AR-15 very closely resembles. The AR-15 is the civilian version that is semi-automatic, compared to the select-fire/automatic versions used by the military. Still, they are basically the same thing which is pretty cool if you ask me.

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2. It’s Easy to Shoot

Your standard AR-15 will shoot the 5.56x45mm round, which is extremely easy to shoot and does not have much recoil. This is a very accurate round, and almost all shooters can easily handle it. Not only that, but most AR’s are generally very lightweight when compared to other firearms.

3. Best Ergonomics Around

They call these guns “legos for men” for a reason. The AR-15 platform is extremely modular and can be quickly changed or set up differently depending on the shooter, or even the preferred way of shooting. Since it consists of both a lower and upper portion, these parts can be swapped out in seconds, giving you the chance to shoot how you like.

In addition to the design, there are literally thousands of different accessories out on the market for the AR-15. All of these can be used to change the look, feel, and performance of the gun, and match your own personality and intended use.

AR-15 Ammunition


History of the AR-15

The AR-15 was originally designed as a lighter weight alternative to the 7.62x51mm AR-10 that was also developed for use by the military. Eugene Stoner, the creator, worked for the company Armalite, and they soon found that the smaller 5.56x45mm round allowed soldiers to carry a lot more ammunition in the field.

In the late 1950s, Armalite ended up selling the rights to the AR-10 and the AR-15 to Colt. After some development, Colt produced the M16, a select-fire rifle with a longer barrel. There is a common misconception in the world that “AR” stands for “assault rifle” or even “automatic rifle”, when, in reality, AR stands for “Armalite” from the original manufacturer.

The M4 later came out and saw a few design changes, the biggest being a shorter barrel and a carbine length gas system. This is what most modern AR-15’s are based upon, and they are basically the civilian semi-automatic versions of the M4.

Although Colt technically still owns the rights to the AR-10 and AR-15, most people still refer to these guns, even if produced by different manufacturers (and there is a lot of them) as the AR-15. Now with some of the basic history out of the way, let’s get to the real question… should you buy an AR-15 or build one yourself?

Building or Buying

Many people come across this question when it comes to AR-15s as it is actually pretty simple to assemble a complete firearm, even without a ton of experience. That being said, we would highly recommend if you are getting your first AR, try to get a complete rifle from a reputable manufacturer.

This way you can become more familiar with the platform before trying to tackle the job of completely assembling one yourself. At the very least, try to get a complete upper assembly and build the lower receiver. The lower receivers are much more simple to assemble, and when you are done you can simply snap the upper on and boom! You are ready to go shooting!

Of course, you can also purchase a complete upper AND a complete lower. This will actually save you some money, as companies are charged an 11% tax on complete firearms. Since the upper isn’t considered a complete firearm, you are only paying that tax on the lower, which is generally less expensive than the upper receiver.

Of course, buying a complete gun comes with a lot of added benefits. For one, you eliminate many potential headaches from buying a complete gun than trying to assemble one yourself. On top of that, most firearms come complete with a warranty from the manufacturer.

A gun straight from the factory doesn’t really cost too much more either, and it will also hold its resale value much better than a Frankenstein gun built from multiple different companies should you decide to sell it in the future.

But there is still something very satisfying about shooting something that you built with your own two hands. After getting your first AR-15 from a solid company, you might want to give it a try and see how you like building one yourself!

Now let’s dive into some of the various parts of the AR-15 platform, and some things you might want to consider before buying an AR or if you are buying the parts to assemble one yourself.

AR-15 Parts

Like we mentioned before, the AR-15 platform is very modular and just about every single part on the gun can be easily swapped or changed out. This is why they are known as “legos for men” as they can be easily built or modified depending on the gun owner’s likes and dislikes. While we won’t get into every single part of the gun, let’s go over some of the more important parts like the barrel, bolt carrier group, and triggers.


Since most AR-15’s are chambered for 5.56x45mm NATO or .223 Remington, we will stick to those when talking about specific parts, especially the barrels. Although barrels are available for a wide variety of different calibers, all the way from the small .22LR to the giant .50 Beowulf.

AR-15 Barrels


The 5.56 barrel is much more common, as you can shoot both 5.56 AND .223 out of it because of its looser tolerances, while with a .223 barrel you can only shoot .223. There are also some hybrid barrels that are designed for specific purposes and that can also shoot both.

Barrel Length

To be in accordance with federal rules and regulations, all rifles must have a barrel length of 16 inches. To have a device such as a muzzle brake, compensator, or flash hider count towards that 16 inches, it must be permanently attached.

For example, if you have a 14.5-inch barrel, you can permanently pin or weld a muzzle device in order to make it over 16 inches which puts it into compliance. You should always be aware, however, of any state or local laws that might have even stricter stipulations against barrel lengths and what type of muzzle devices are allowed on the end of a barrel.

So most people will go with a 16-inch barrel so that they can swap out for different muzzle devices. The most common lengths that you will see for sale are 16, 18, and 20 inches. So what is the best one for you?

AR-15 Rifle


While most people tend to agree that a longer barrel is meant for more accuracy, this is not always the case. You can achieve some amazing accuracy out of a 16inch barrel because of how much shorter and stiffer it is. This will make it much less susceptible to things like barrel whip and be much easier to control with its smaller size.

The one thing a longer barrel will give you, however, is more velocity. This is because there is more space for the powder to burn, therefore giving the bullet more time to speed up before it leaves the barrel. The faster a bullet is moving, the less it is affected by things like gravity and wind as it advances toward a target.

An average 16-inch barrel will be more than enough for any shooting out to about 400 yards, but at that distance a standard 55-grain bullet will start to be heavily affected by outside pressures (like the wind and gravity that we mentioned). For longer distances, go with a heavier bullet such as 62, 77, or even 80-grain bullets.

Lastly, you want to consider weight and maneuverability. The longer the barrel, the heavier it is going to be and harder to move around with. The shorter the barrel, the easier it will be to hold, shoot, and carry around. A lot of different things to consider when it comes to the barrel, and we are just getting started!

Barrel Twist

Another thing to consider with barrels is the twist rate. This is shown as a 1 plus a number (such as 1:9) which is meant to mean one twist per 9 inches. So, the longer the bullet you are shooting, the faster the twist you will want.

The most common twist rate found in most AR-15’s is the 1:9, as the 55 grain round is the most popular and available.

Bolt Carrier Groups

Now let’s move onto another important part of the gun, the bolt carrier group. The bolt of an AR-15 is found within the bolt carrier, and all of these parts together make up the bolt carrier group or BCG.

The BCG is what moves back and forth within the gun, and as it moves forward, it will take a round out of the magazine and put it into the chamber. When the trigger is pulled, the hammer releases and hits the firing pin, which is also found in the BCG.

BCG’s come in two varieties, both semi-auto and full-auto. This does not make your gun full auto or semi-auto, and instead, the full auto BCG’s are used to slow down the cycling rate because of its increased mass.

AR-15 BCM Bolt Carrier Group AUTO MP 2


A full-auto BCG has a small shroud to protect the firing pin, and essentially performs the same function as a semi-auto. You can choose either one and not go wrong, but many high-end manufacturers usually will put full-auto BCG’s in their guns.

In addition to the type of BCG, there are also a few options when it comes to coatings found on them. These are supposed to make the BCG much easier to clean, run on less lubrication, and provide overall durability and reliability to the functioning of the gun.

You can choose a BCG with a coating such as nickel boron, hard chrome, black nitride, or titanium nitride, but honestly if you keep your regular BCG clean and lubricated, you should never have a problem with it!

Triggers, Handguards, and More

For your first AR-15, it would probably be best to stick with a standard, mil-spec trigger. While basic and sometimes gritty, it is super reliable and helps you learn the basics. When you are ready for an upgrade, there are some excellent single-stage and two-stage triggers out on the market, with plenty to choose from.

 AR-15 triggers and handguard

The same applies to the handguard and most of the other furniture on a gun. If you are new to the AR platform, just stick with the basics. Remember that you can always change things out down the road after becoming more familiar with the firearm, and after using it for some time, you might get a feel for what you like and dislike.

There is no point in spending a ton of money on a custom gun or custom parts if you do not know what you prefer yet. You will also want to consider potential uses. Are you wanting an AR-15 for home defense? A range toy? A varmint rifle? Your intended use will also determine how you set up your rifle, especially things like the handguard, buttstock, etc.

High-Quality AR-15 Manufacturers

Now, let’s get to the good stuff! There are plenty of good AR-15 manufacturers out there, but we want to go through some of what are considered the best depending on your budget. Just remember, you get what you pay for! If you want a higher quality firearm, it is going to cost more. On the flip side, if you just want a gun you can beat up at the range, even the budget options will easily get the job done!

High-end AR-15 Companies

The companies on this list are generally considered to make some of the best AR-15’s in the world. These are companies who do not cut corners with their products, and their guns are the most reliable that you will find. If you are looking for one of the best, these companies are a great place to start!

Daniel Defense
Bravo Company (BCM)
Yankee Hill Machine

Mid-tier AR-15 Companies

These are great companies that produce excellent guns, without paying quite the premium. You might want to thoroughly test a rifle at the range with some extensive use before trusting your life to it, but after breaking them in, guns from any of these companies are sure to make a great addition to your firearm collection!

Aero Precision
Palmetto State Armory (PSA)
Sig Sauer
Smith and Wesson

Budget AR-15 Companies

There is nothing wrong with the companies on this list, and they make some great beginner AR-15’s because of how affordable they are. They can also be just as reliable too, just make sure to put them to the test at the range first.


The Best AR-15 Rifles

Now here is our list for some of the best complete rifles that you might want to consider. This list is our own opinion, but all of these rifles have a proven track record and are generally considered to be some of the best all-around AR-15 rifles being produced right now!


Bravo Company Manufacturing (BCM) Recce-16 AR-15 rifle 

1. Bravo Company Manufacturing (BCM) Recce-16

In my honest opinion, BCM is the best bang for your buck when it comes to quality versus price tag. This is my gun of choice, and it has never once had a single problem. BCM also offers complete lowers and uppers if you want to mix and match or only buy one piece at a time, and overall I would say that you cannot go wrong with anything made by this company.

 Daniel Defense DDM4 AR-15 rifle

2. Daniel Defense DDM4

Now if you want the best of the best, this is it. Daniel Defense is regarded as one of, if not the best producer of AR-15’s. The DDM4 is a great all-around rifle for anyone looking for a gun that can do anything, but Daniel Defense offers plenty of other options in carbine and rifle-length gas systems, as well as different furniture and configurations. The only downside to buying from Daniel Defense is that you will be paying a premium to have the best!

 Aero Precision M4E1 AR-15 rifle

3. Aero Precision M4E1

Aero Precision is most well known for its quality AR-15 parts among shooters who assemble their own builds, but many are unaware that Aero Precision produces some very high-quality complete uppers and lowers. One of these is the M4E1. This is one of my favorite complete uppers and is just about as reliable as they get. Plus, it comes in at a great price.

 Smith and Wesson M&P Sport II AR-15 rifle

4. Smith and Wesson M&P Sport II

Now we are getting to our more budget-friendly options on our list, but there is still some great quality and reliability to be had. The Smith and Wesson M&P Sport II is one of the best options for beginners wanting to get into the AR-15 world with a complete firearm, and its price is just about as good as you can get with still owning a reliable, accurate AR-15 rifle.

 Palmetto State Armory AR-15 rifle

5. Palmetto State Armory AR-15

For those that like to build AR-15’s on a budget, Palmetto State Armory is your best friend! They also sell complete rifles, like the PA-15. Like the Smith and Wesson, this is more of an entry-level AR-15, but since PSA manufacturers everything themselves in-house, the quality is very high for the price tag. This is another great option if you are just starting out and want to become more familiar with the AR-15!



Hopefully, now you have a better understanding of the AR-15 in general, and some of the many options this platform gives you. Whether you are just starting out, or want to upgrade your current rifle, there are plenty of options and great companies out there to keep you shooting!


Written by Steven Lines

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Steven Lines is a hunter and firearm enthusiast from Arizona, USA. He has been shooting and hunting since a child, and also enjoys long-range target shooting and collecting firearms. Steven works as a hunting guide in Arizona during his spare time and runs a Youtube channel dedicated to sharing his outdoor adventures with others.