Best AR 15 Rifle [Best Choices] (Former Marine’s Buying Guide)

ar 15 brands

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The AR 15 is controversial, but a fantastic rifle. While AR stands for Armalite it might as well stand for America’s rifle. It’s by far the most popular rifle in the United States.

Due to its popularity, the rifle is absolutely everywhere and it absolutely every configuration you could imagine. Buying an AR 15 can be a confusing process. With so many out there you may not even know where to start.

That brings us here, to our expansive and in-depth AR 15 buyer’s guide. Dive in, and at the end you’ll have a much better idea about everything the AR 15 encompasses.

Throughout the guide, we’ll have blurbs point out what we think is the best choice for the new AR owner. This takes into account durability, usefulness, price, and of course quality. These blurbs will give you a good idea of the parts needed to build a reliable and affordable rifle.

Why own an AR 15?

Why would one want to own an AR 15? Especially when its compared to other semi-automatic, box fed, intermediate caliber rifles on the market? That is a good question, but it doesn’t have a simple answer. In fact, it has several answers.


Ergonomics play a large role in how well you can shoot the gun. This includes long range shooting, multiple position shooting, as well as shooting under stress. The better the ergonomics the easier it is to handle the gun.

ar 15 reviews

The AR 15’s design reeks of awesome ergonomics. Eugene Stoner, the AR 15s designer, knew what he was doing when he assembled his first rifle. Every piece that needs to be activated by the shooter is close and at hand. From the gun’s safety to the charging handle.

The manual of arms of an AR 15 is simple. Simple enough that the US Army and US Marine Corps takes thousands of 18-year old recruits who have never fired a gun and has them qualified by the end of boot camp.

If the rifle isn’t ergonomic enough as is, it just so happens to be the most modular rifle platform in existence.


This is the perfect time to mention the modularity of the AR 15 design. Due to its popularity among the military, police, and civilians the aftermarket is massive. You can take an AR 15 and transform it in any way you want.

There are massive amounts of stocks, handguards, optics, BCGS, barrel, magazines and more that allow you to customize your gun in almost any direction you want. Every component on an AR 15 can be swapped for something different.

tactical ar 15

The AR 15 is the Barbie doll of the gun world. The number of ar accessories designed for it boggles the mind. This is a good thing because you can build a rifle that’s truly yours.


AR 15s are produced by almost everyone. From corporate giants like S&W to small mom and pop custom shops. With this massive market presence, you can find AR 15s for as little as $400 dollars new in box to $4,000 dollar rifles made for Tier 1 operators.

You can spend as much, or as little as you want on an AR 15. The rifles themselves are affordable, and so is the aftermarket. Ammo, magazines, sights, and more are easy to find and come in at all price levels.

On ammo certain calibers will obviously be much more expensive than others, but the standard 223/5.56 ammo the AR 15 is traditionally chambered in incredibly affordable.


The AR 15 is an exceptionally accurate rifle, especially at the price point, they are available at. Even a cheap AR 15 can make accurate shots on a man-sized target out to 500 yards. The AR 15 is not only inherently mechanically accurate but due to the modularity, it's easy to shoot.


The AR 15 gets a bad rap for reliability due to the early performance of the M16 in Vietnam. This was not due to the guns design, but due to the use of wrong gun powder, a lack of cleaning kits, and the bore was not chrome lined as it should have been.

The AR 15 is a very reliable weapon that functions without issue as long as you clean occasionally. It’s a professional’s weapon and it functions as such. From personal experience, I will tell you the guns run and run well.

ar guns

I’ve put tens of thousands of rounds downrange as both a Marine and civilian and rarely have I run into any malfunctions. In fact, none come to mind beyond bad magazines.

What Kind of AR 15 Do You Want? A Rifle, Pistol, or SBR?

When you are looking for an AR 15 you have to consider what kind you want. Due to American gun laws, there are three different categories of the AR 15. Each type falls into a different legal definition.


ar15 rifle

The basic AR 15 is a rifle with a barrel of at least 16 inches with a stock. This is the most common AR 15 on the market and it’s an effective tool. It’s well suited for most ranges and is accurate out to 500 yards.


ar 15 sbr

SBR, or Short barreled rifle, is a classification of rifle that results from having a barrel less than 16 inches. This classification is regulated heavily under federal law and requires an extensive application process, a 200-dollar tax, and months of waiting for an approval.

An SBR is best rifle for home defense due to its short size, but the shorter barrel may affect ballistic performance.


ar 15 pistol

Yes, the AR 15 can be made into a pistol. This is due to American gun laws. An AR pistol can still fire rifle rounds but is considered a pistol because the barrel is shorter than 16 inches and it lacks a stock.

AR pistols can be a bit unwieldy and are best suited as range toys. These little guns are fun, but they aren’t for everyone.

For Beginners Blurb - Your first AR 15 should be a traditional rifle. They are the easiest to shoot, easiest to find, and often the most useful and versatile.

best budget ar15

Aero Precision AR 15

Barrel Length


Twist Rate



5.56 NATO

Gas System


To Build or To Buy?

The AR 15 is a very simple rifle. A user can take one apart with nothing more than a couple of basic tools and access to the internet. The AR 15 is also a rifle that's so popular you can build one unique to yourself.

You can purchase each and every part separately to build and assemble your very own AR 15. This allows you to mix and match and choose the parts you want. You can build the exact rifle you want.

Building is beneficial because you learn the insides and outsides of the rifle. You can learn how the rifle works, and possibly diagnose issues.

ar-15 parts diagram

If you just want an AR 15 you can always buy. Buying a rifle ensures everything is assembled correctly and each and every part comes set from the manufacturer. Building is easy but buying is even easier.

If I’d be looking for an extremely high end AR 15 I'd likely buy it over build it. I can customize furniture later. If I was spending a large sum of money on a high-end rifle I’d prefer to buy and ensure competent professionals built the gun.

I’d also rather buy a gun if I was buying for duty and home defense use. Again, this goes back to a certain degree of paranoia and want to ensure the gun is reliable and will always go bang when I pull the trigger.

top rated ar 15

If I just wanted a low to mid-range AR I’d likely build it. Building an AR, the proper way means having the right tools on hand, as well as being patient and knowing how to do the small things right. Sometimes staking a gas block is a little trickier than it seems.

Check out our guide for the best scopes for AR 15 coyote Hunting.


Oh boy, you have a big choice to make when it comes to choosing the right caliber for your AR 15. How many calibers could the AR 15 possibly be chambered in? Pretty much all of them…

Different calibers mean different magazines, different bolts, triggers, buffers, muzzle devices and more. However, one thing that remains the same is that these are AR 15s through and through.

what caliber is an ar-15? To a degree. If you count wildcat cartridges we could an entire article on those. However, the most common chamberings are as follows.


5.56/223 bullet

The old standard for the AR 15. This is the caliber the rifle was designed for, and what you’ll find most rifles chambered in. The commonality of these cartridge means its cheap, reliable, and is one of the most common rounds on the market.

300 Blackout 

300 blackout

The newest bell of the ball in AR calibers is the 300 Blackout. This 30 caliber round uses standard 223/5.56 AR 15 parts except the barrel and gas system. This round is designed to be easily suppressed and to be fired from short barrels.


9mm bullets

2017 was a big year for pistol caliber carbines. The 9mm round has been a favorite for these carbines for some time and AR model rifles have been chambered in 9mm forever. The modern 9mm AR will either use Glock or Colt SMG magazines. 9mm rifles are lightweight, easy shooting, and affordable rifles.

22 LR 


With the right bolt, you can reliably and easily fire the affordable 22 LR. These 22 ARs do require a special bolt if you want to use standard AR parts. Other options exist that aren’t exactly ARs but built to look like them. You can also convert your 5.56 to a 22 LR easily enough.


7.62x39 bullet

The old AK round has found its way into the AR. This requires a rather odd-looking magazine, and a stronger hammer and firing pin but they will cycle. This creates an interesting rifle that’s perfect for the under 300 Yard range. Plus, 7.62x39 is dirt cheap. However, using a 7.62x39 rifle scope can help improve accuracy and increase the effective range of the rifle, making it easier to hit targets at longer distances or in challenging shooting conditions.

Additional Calibers

Here are a few less common calibers you can chamber an AR 15 in.

  • .22 PPC
  • .22 Nosler
  • .224 Valkyrie
  • .223 Winchester Magnum
  • .243 Winchester Magnum
  • .25 Winchester  Magnum
  • .25-45 Sharps
  • .277 Wolverine
  • .30 Carbine
  • .30 Remington AR
  • 300 OSSM
  • 375 SOCOM
  • 7.92x33mm Kurz
  • .40 S&W
  • .410 Shotgun
  • .45 ACP
  • .450 Bushmaster
  • .458 SOCOM
  • .50 Action Express
  • .50 Beowulf
  • 5.45×39mm
  • FN 5.7×28mm
  • 6.5mm Grendel
  • 6.8mm Remington SPC
  • 7.62×37mm Mustang
  • 10mm Auto
Our Guides:

For Beginner’s Blurb - 5.56/223 is what the AR 15 was originally designed to function with and is the best choice for new AR owners. Most magazines, parts, and other accessories are designed around the 5.56/223.

Check out our guide on 'effective range of AR 15'.


Bullet Style



55 Grains


223 Remington

Muzzle Energy


Billet or Forged?

When it comes time to choose your upper and best lower receiversor your complete rifle, you’ll have to choose between billet or forged receivers.

Forged Receivers are the traditional, mil-spec option. These are the stronger of the two. The difference is small, and inconsequential though, unless you are measuring the foot pounds required to tear one apart. Forged receivers are easier to make and much more affordable.

ar 15 parts

Billet receivers start life as one solid block of aluminum. They are then milled into a lower receiver. The only real benefit from a billet receiver is that they can be customized to look extremely unique.

ar 15 billet

This can range from nothing more than cleaner, sharper lines to fully customized, one of a kind lowers. The downside is of course billet receivers are a much more expensive option than forged receivers.

For Beginners Blurb - A forged lower and upper receiver is the most affordable, and strongest choice.

AR-15 Lower Reciever


Anderson Manufacturing


223/5.56 Nato





All About Barrels

You’d think in the world of guns barrels would be something simple. However, in the world of AR 15s, you have dozens of options for different barrels. These options have advantages, disadvantages, and most serve some unique purpose or another.

We are going to dive into barrels and point out as many differences as possible.


Length is a big deal when it comes to barrels. You can basically build an AR with a barrel length of anywhere from 24 inches to 4 inches. There are a few things to understand about barrel length and why it affects your gun.


In the United States, a rifle’s barrel must be 16 inches or you must register the rifle as a short-barreled rifle, pay a tax stamp, and wait for 4 to 6 months for approval. You can, however, have a barrel less than 16 inches on an AR pistol.

What’s really important to keep in mind is 14.5-inch barrels. These are common barrels on the market and with the right muzzle device, they will be over 16 inches. That sounds great, right?

Well, the problem is unless that muzzle device is permanently attached that is still a short-barreled rifle.

Ballistic Performance

Barrel length will also affect ballistic performance. The right barrel length for getting every little bit of ballistic potential is going to be dependent on your caliber. Different rounds have different ballistic performance and will require different barrel lengths.

For example, the 5.56/223 is designed for a 20-inch barrel and reaches its peak velocity in a 20 inch barrel. Although, the round is still quite capable out of 16-inch barrels. And it can hit long distance target pretty accurately. And using optics also increases your hit ratio. You can go with inexpensive AR optics if you don't want to spend too much.

The 300 Blackout, on the other hand, reaches peak ballistic performance out of a 9-inch barrel. As you can see the differences between the two are massive and important to recognize.

ar 15 model

Because there are so many calibers out there I can’t list every potential caliber and the right barrel for ballistic performance. That will be on you to research and learn about. The info is out there, you just need to look for it.

The other length consideration goes to the purpose of the rifle. A rifle designed for hunting or long-range shooting can greatly benefit from a longer barrel. A rifle designed for home defense and duty use would work best with a shorter barrel for enhanced maneuverability.

Barrel Profile

Your barrel profile is essentially its degree of thickness. This is another consideration you’ll need to make based on how you plan to use your rifle. Different thickness level delivers different performance levels.

There are 3 main barrel profiles used in the industry. Due to the number of people making AR 15s and barrel, there are also tons of different non-standardized profiles. These non-standardized profiles are usually designed due to material differences or for specialized rifle roles.

The 3 main types are as follows:

Light Profile - These thin, lightweight, and often short barrels are perfect for a build focused on light weight. They are occasionally known as pencil barrels and the lightweight nature makes them easy to hold in a firing position for extended amounts of time.

ar 15 pencil barrel

Light profile barrels do tend to heat up much faster than standard barrels. This causes them to be slightly less precise. Light profile barrels are most commonly .625 inches thick.

Government/M4 Profile - Government or M4 profile barrels are basically a medium thickness barrel. The barrel itself has a cutout near the rear to accommodate an M203. Everything forward of the front sight base is a medium thickness barrel

medium thickness ar 15 barrel

This is a solid compromise of both weight and barrel integrity. They will heat up slower than light barrel but provide still maintain a comfortable amount of weight. These barrels are typically .750 inches thick.

Heavy Profile - Heavy barrels are made for long range and high-volume shooting. Their thickness level makes them rigid and less susceptible to barrel flex. They also take longer to heat up, therefore your groups won’t open up as fast.

ar 15 heavy barrel

The downside is in the name. These barrels are heavy. They are really made for rifles that will be rested on bipods or sandbags prior to taking a shot. They are most commonly .936 inches in diameter.

Twist Rate

Twist rate is the measurement of rifling inside a barrel. This is the distance in inches it takes for a bullet to achieve one full rotation inside the barrel. Twist rate is most commonly denoted by something like 1:9.

This means the bullet rotates completely 1 time every 9 inches. Twist rates vary greatly between rifles and calibers. Some are faster than others. For example, a 1:7 twist rate is faster than a 1:9.

It’s important to match ammo weight to twist rates. The faster the twist rate the better it stabilizes heavy rounds. Different calibers mean different weights and therefore different twist rates.

It’s best to independently research your caliber, as well as the weight of the projectile you plan to fire most often. Firing a projectile through a barrel with a faster or slower twist rate won’t damage the gun, but it may decrease your accuracy and effective range.

What's the Barrel Made From?

AR 15 barrels are made from a variety of different metals. These different metals can change the accuracy as well as the durability of a barrel. Here are the most common barrel materials.

  • 4140 - A general purpose steel barrel that is affordable and effective.
  • 4150 - A steel that features 10% more carbon, makes the barrel slightly stronger.
  • 4150 CMV - Essentially a mil spec barrel designed to withstand full auto fire over long periods of time.
  • Stainless Steel - An option that delivers greater accuracy but has a shorter barrel life.
  • Carbon Fiber - The latest and greatest. The Jury is still out, but carbon fiber barrels are extremely accurate, durable and lightweight. They are also very expensive.

Choosing a barrel will be based on how you are using your rifle. Your average carbine will be well served by a 4140 or 4150 barrel. They aren’t fancy, but they’ll last forever.

The 4150 CMV isn’t necessarily needed unless you are shooting full auto, or an absolute ton of rounds in a short period of time.

ar15 carbon fiber barrel

Stainless steel and carbon fiber barrels are best suited for precision shooting, as well as long range shooting.

What’s on The Inside (of barrels) Is What Matters

The inside of the barrel, known as the bore, will often have a lining material. These materials can do a few different things for you.

No Lining - Cheaper for sure, but zero corrosion protection.

Chrome Lined - These are the most common out there and it's the military standard. The chrome lining will protect the bore from corrosion and rust. Some say there is a decrease in accuracy, but it’s so little that you’d have to measure it with a micrometer.

Chrome Lined

Ferritic Nitrocarburizing - Gives the bore both corrosion resistance and supposedly aids in accuracy. Can be quite expensive. Also known as Tennifer, Melonite, and Nitride.

For Beginner’s Blurb - A 16 Inch 4140/4150/4150 CMV barrel, with a chrome lining, with a 1 in 9 twist. A 1:7 twist allows you to shoot most 5.56 loads accurately. 16 inches is industry standard and any of the listed steels will last forever.

Brownell's 16" Barrel


5.56 mm NATO







Choose your Operating System - Gas Piston, Direct Impingement, and Blowback

It's easy to compare the AR 15 to a computer. You have tons of options when it comes to building or buying. Options that improve performance, looks, and everything in between.

You can also choose different operating systems. The three main AR 15 operating systems are the gas piston, direct impingement, and blowback.

Direct impingement, or DI, is the standard AR 15 operating system. With this system gas from the last round fired is pushed into the upper receiver and causes the BCG to be thrown backward. This ejects the round, hits the buffer, and then reloads the rifle’s chamber.

DI was what the gun was designed to work with. It’s reliable, affordable, well proven, and more importantly it’s accurate.

Gas Piston guns place a piston where the gas tube would be. The last round fired propels the piston rearwards where it makes contact with the BCG and sends it backwards. This then ejects the round before meeting the buffer and reloading the rifle’s chamber.

Gas piston guns are costly but run cleaner and cooler at the sake of accuracy.

Blowback is what’s used for pistol caliber and rimfire guns. This is a simple system that simply uses the energy from a fired cartridge to send the bolt rearward. This simple system cannot be used with more powerful rounds without a locked breech.

For Beginner’s Blurb - DI guns are much better suited for the first time AR owner.

Gas Systems

We just talked about operating systems, and now we are going to talk gas systems. First and foremost, this has nothing to do with gas piston guns or blowback guns. This is all about direct impingement guns.

Gas systems are composed of a gas block and gas tube. The differences in gas systems is based on both barrel length and caliber. Certain calibers, like 300 Blackout, will use a set gas system regardless of the barrel length.

With most common calibers your gas systems will depend on your barrel length to a large degree. The most common AR 15 gas systems are:

Pistol Length - Designed for AR pistols and SBRs this gas system is for barrels less than 10 inches.

ar 15 gas system pistol

Carbine - Carbines can be run in larger pistols and SBRs, and rifles with barrels as long as 16 inches. This gas system is designed for barrels longer than 10 inches and up to 18 inches.

ar 15 gas system carbine

Mid Length - Mid-length gas systems as designed for rifle barrels between 14 to 20 inches.

ar 15 gas system midlength

Rifle Length - Rifle length gas systems are designed for barrels 16 inches and beyond. Traditionally these systems are designed for rifles with 20-inch barrels. However, rifles known as dissipators exist. These are 16-inch barreled uppers with a rifle length gas system.

ar 15 gas system rifle length
Choosing a Gas System

Generally, you want to use the longest gas system possible. This results in a smoother shooting rifle with less overall recoil. For example, if my rifle has a 16-inch barrel I can use a carbine or mid length gas system.

I’d go with a mid length system in this situation.

For Beginner’s Blurb - A Mid Length Gas system is perfect for a 16-inch barrel and will ensure your gun is getting plenty of gas, but also helps mitigate over gassing.


COLT - Gas System



Gas System

Mid Length



Made In


The Heart and Souls of the Rifle - The BCG

The BCG, or bolt carrier group, is the heart of your rifle. As an assembly it loads the chamber, fires the round, and then ejects. It repeats the process over and over again.

A solid BCG is a must have for your rifle. Like every other part we’ve talked about here there are multiple options for your AR 15.

Full Auto

Let’s get this out of the way now, a full auto bolt carrier does not make your gun fully automatic. It’s simply rated for full auto fire. These FA BCGs are tough, affordable, and the most common BCG on the market.

Semi Auto

Semi auto, of SA, BCGs are slightly shorter and therefore lighter than the standard FA BCG. Semi-auto BCGs were somewhat popular in the 90s and were created to satisfy some anti-gun politicians. They are dependable, reliable, but nowhere near as common as FA BCGs.

Lightweight BCGS

Lightweight BCGs are designed to do two things. First, they trim weight from your entire build. A lot of AR owners are building super lightweight rifles and a lightweight carrier trims precious ounces off your lightweight build.

The second reason people like lightweight bolt carrier groups is the fact they can help reduce recoil. In an AR 15 the bolt carrier group is shot backwards, so the weight of the BCG affects how the weapon feels as it recoils.

A lighter BCG means less mass moving rearward, which results in lower recoil.

Lightweight BCGS

The downsides are that a lightweight BCG is the fact you need an adjustable gas block to really squeeze the most of a lightweight BCG. They also tend to be less durable due to the reduced mass, and a lot more expensive.

Aluminum BCGs for example are very light BCGs, but they have a considerably reduced service life. A strong alternative to aluminum for a lightweight BCG is titanium. Titanium BCGs are much stronger, but also remain lightweight.

The issue there is titanium BCGs can cost hundreds of dollars.

BCG Coatings

Like the insides of barrels BCGs are coated for a variety of reasons. This includes durability and corrosion resistance. The most common coating are bolt carrier groups is phosphate, nickel boron, ion bonded, and titanium nitride.

Phosphate is the industry standard and the mil-spec option. Phosphate is extremely strong and very resistant to heat and corrosion. Phosphate is also going to be on the more affordable BCGs.

Nickel Boron is a material applied via auto catalytic reaction and results in a bright and shining gold or silver finish. Nickel boron is extremely corrosion resistant and extremely smooth. This reduces friction and helps the gun run longer between cleanings.

nickel boron coating

The downside is that nickel boron can chip and breakdown after a few years of heavy use.

Ion Bonded finishes combine the positive qualities of both phosphate and nickel boron to produce a friction reduced, extremely durable coating. Ion bonding will last nearly forever and is resistant to heat and corrosion.

Ion bonded BCGs are quite pricey, and not as slick as nickel boron, but they come in pretty close.

Titanium Nitride

BCG coatings titanium

If you have the money to spend a titanium nitride coated BCG. This is truly the best of all worlds. It’s just as slick as nickel boron and just as tough as phosphate. It’s incredibly durable and will last forever.

It even results in a slick gold like appearance which admittedly looks great. The downside is of course cost. This coating makes a BCG quite pricey.

For Beginner’s Blurb - A simple full auto phosphate coated BCG will serve you well. Go with a mil spec model and you’ll be good to go.

M16 Bolt Carrier Group

6 Replies to “Best AR 15 Rifle [Best Choices] (Former Marine’s Buying Guide)”
  1. Travis this is my first ar build. I’ve bought a Ruger elite bottom receiver. Next I want theDaniel Defense M4A1 upper. Do you think this will be a good match? I wanted to totally build it from the ground up but I think I bit off more than I could chew. Lol I’ll gonna do that on the ar10 in 9mm platform.

  2. Travis thanks for posting this. The info is great for everyone from beginners to experienced shooters.

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