Find The Best AR-15 Barrel for the Money (16″, 14.5″, 18″+, and SBR Lengths)

Table of Contents

For those who just want our picks, here's the links:

• Best AR-15 Barrel for the Money
• Best Cold Hammer Forged AR-15 Barrel

If you want to know what to look for and how we came to our decisions, we cover this below, including:

• Calibers/Chamberings
• Twist Rate
• Barrel Length
• Barrel Profiles
• Barrel Materials and Linings
• Forging Process
• Manufacturer Testing Processes
• Gas System Lengths

Calibers/Chamberings

Though the AR platform has been adapted and used for a huge variety of calibers, we're going to be focusing on the AR-15's standard 5.56 NATO / .223 caliber. In addition to being the "default" caliber, it's also the caliber most commonly used by civilians, the U.S. Military and NATO forces.

Without getting bogged down in the details, there are a few basic things you need to know:

• Barrels labeled 5.56 can shoot both 5.56x45 NATO and .223 Remington.
• Barrels labeled .223 can likely only shoot .223 safely, as they are not rated for the higher pressure of 5.56. With that said, some manufacturers label their products .223 because they're designed to perform best with .223, but they can still use 5.56. If you do have a .223 barrel, always confirm with the manufacturer that it's safe to use 5.56 before attempting to do so.
• Barrels labeled .223 Wylde are typically safe to use with both 5.56 and .223, though they were designed to take advantage of .223's accuracy advantage. These barrels are frequently used for some shooting competitions with high-grain ammo.

If you're not sure what to pick, we'd recommend getting a 5.56 barrel  or .223 Wylde Barrel. It's better to be able to shoot both calibers than just 223. 

Twist Rate

A barrel's twist rate is the distance it takes for the barrel's rifling to make a complete 360 revolution. This is measured in inches and commonly displayed as a ratio like 1:7, 1/7, 1-7, or 1 in 7. In this example, the rifling completes a 360 revolution every 7 inches. If you're still experiencing any confusion, the picture to the right should help.

The optimal twist rate for a bullet is calculated based on the projectile's length, diameter, and weight. Since we're focusing specifically on 5.56 and .223 calibers, bullet weight is the most important thing to pay attention to.

Here are the general guidelines for twist rate in relation to bullet weight (in grains).

Bullet Weight (Grain)	Optimal Twist Rate
40 Grain	1:12
55 Grain	1:9
62 Grain	1:8 or 1:7
77 Grain	1:7 or 1:8
80 Grain	1:7

Here's another look at bullet performance in AR-15 Barrels with the most common twist rates.

For the average person, without a specific goal in mind, you'll likely be shooting 55-grain .223 most of the time, as it's the cheapest AR-15 ammo available. You can either choose to optimize your AR-15's barrel for this by going for a 1:9 twist... Or you can not.

I frequently shoot 55 GR .223 out of my 1:7 barrels at distances below 100 yards. When I occasionally want to push out to further distances, I use a heavier bullet, which is best for long-range shooting anyway.

Basically, I'd rather optimize performance when it's most important—at long range—as any drop in performance doesn't really matter at closer ranges in my opinion.

Given this preference, I usually end up with a 1:7 twist 5.56 rated barrel, though the less common 1:8 is likely best if you can find one that fits your other criteria.

Barrel Length

Perhaps the most important factor to consider when choosing an AR-15 barrel is its length. There are legal, performance, and purpose considerations to take into account.

Legality

The federal minimum length for a rifle barrel is 16". PERMANENTLY attached muzzle devices (e.g. welded on devices) are included in this length, so it's common to see 14.5" barrels with permanently attached muzzle devices sold in complete rifles/uppers or as components to be used in a rifle.

If you want to build or buy a rifle with a barrel shorter than 16", there are two options.

• Short-Barreled Rifles (SBRs) - A short-barreled rifle is a rifle with a barrel length less than 16" or with an overall length less than 26". It is an NFA item, meaning you must first complete and submit a Form 1 to the  Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF), pay a $200 tax stamp, and wait for ATF approval. Do NOT build an SBR before getting approved. The approval process can take 6-10 months.
• AR Pistols - The easier option is to build an AR-15 pistol, which if done correctly, is NOT legally a rifle. You can NOT attach a shoulder stock to an AR Pistol, as that would make it an SBR. You can, however, attach a pistol brace—though it's legally murky as to whether or not you can shoulder it. You also can NOT attach a vertical foregrip to a pistol with an overall length less than 26". With that being said, I avoid attaching any vertical foregrips to AR pistol builds even when they exceed a 26" OAL, as I don't want to be accosted by an uninformed police officer or range employee over an accessory I'd never use anyway.

Disclaimer: We're not lawyers and this is not legal advice. Always do your own research and comply with your federal, state, and local laws.

Performance

Perhaps the most telling study on the performance of AR-15 barrels of varying lengths was this one done by Small Arms Defense Journal. They compared bore pressure and velocity between barrel lengths using 63-grain ammo.

Bore Pressure - Generally, the shorter the barrel, the higher the bore pressure is at bullet exit. Shorter barrels lead to louder shots, greater flash intensity, and more ware on suppressors.

Velocity - Longer barrels generally lead to greater muzzle velocity, though there are diminishing returns at lengths greater than 20".

My Takeaway From the Study - If you're primarily looking for a rifle to shoot at long distances, you should probably use a 20" barrel. For home defense and close quarters tactical use, stay at or above a barrel length of 10.5".

Purpose

Why are you building this AR-15? While some statistics may be worse for an 11.5" barrel than a 20", that doesn't mean a 20" barrel is right for every job. In fact, the U.S. military has been steadily adopting shorter barrels over time, including the M4's 14.5" barrel and even 10.3" barrels used by Special Operations Forces.

A shorter barrel is better for maneuverability and concealability/storage. In other words, a shorter barrel is likely better for a home defense gun, SHTF gun, or truck gun. You can also realistically still hit steel up to 300 yards without being a professional shooter.

Recommendation - If you're not sure what to choose and don't have a specific purpose in mind, I'd recommend either a 16" barrel or 11.5-12.5" (if you're willing to get an SBR or an AR Pistol). A 14.5" barrel with a permanent attachment putting it at 16"+ is another great option, but be sure to put some thought into the muzzle device.

Barrel Profiles

It's not just the length of the barrel you need to consider, but also it's shape, weight, and thickness. There's a variety of different barrel profiles to choose from, which we'll quickly cover the basics of.

This picture (below) from ar15barrels.com is a good illustration of the general differences between AR-15 barrel profiles. With that said, many of the best barrels on the market today are uniquely contoured. 

As the names suggest, lightweight or pencil thin barrels can shave off a significant number of ounces, especially when compared to the heaviest profile options. This comes at a price, however, as they tend to have more barrel whip negatively affecting accuracy. They also get hotter, faster, which exacerbates this problem. That being said, I tend to like these barrels for range-toy builds.

For combat, SHTF, home defense, and general shooting purposes, the best AR-15 barrel choice is usually a medium or gov't profile barrel.

There are also some blended profiles, like Faxon's Gunner, that arguably give you the best characteristics of both the gov't profile and pencil profile.

Barrel Materials & Linings

Barrel Materials

Barrel materials play a role in the accuracy and durability of your rifle. There's a good bit of misinformation, conflation, and BS from manufactures when it comes to the material they use for their barrels. Basically, some try to make it sound like they're using a better material than they actually are.

Thankfully, this doesn't really matter unless you're planning to do a lot of sustained full auto fire... which you're probably not. 

Mil-B-11595E - Commonly considered to be the "best" barrel material option, Mil-B-11595E adheres to military specifications. This is what the U.S. Military uses, and thus, it's likely optimal for combat. If you actually are planning to do a lot of full-auto fire, check with the manufacturer to be sure their barrels are actually Mil-Spec.

4140 and 4150 - You'll see the terms 4140 and 4150 steel thrown around. The 40 & 50 specifies the amount of carbon in the steel, so around .40% or .50%. The higher carbon content is preferred.

You'll also see terms like 4150 CMV or 41V45. These are sometimes up to the above Mil-Spec, but don't necessarily guarantee this. These barrels include Vanadium, which helps make them tougher.

Again, I wouldn't worry too much about this, but you should feel very confident using a "4150 CMV" from a reputable manufacturer. 

Stainless Steel - 416 match grade stainless steel barrels are best if long range accuracy is really important to you. They are, however, more expensive and have shorter lifespans.

Stainless Steel / Carbon Fiber - The new hot trend is barrels with thin layers of stainless steel, wrapped in carbon fiber. Carbon fiber is stronger, lighter, and dissipates heat better than other materials. Naturally, these are the most expensive barrels around. If you can afford it, go for it!

Barrel Lining

Barrel linings improve corrosion resistance, extend barrel life, and make cleaning them a bit easier.

• Chrome Lining is an additive process in which chrome is bonded to the inside of the bore.
• Nitride/Melonite treats the inside of the bore, rather than adding material to it.

Nitride is cheaper, offers similar barrel life when shooting semi-auto, and has less of a negative impact on accuracy. Unless you're shooting full-auto, I see no reason not to go with Nitride.

Barrel Forging

Cold Hammer Forging (CHF or BFH) is a barrel forging process used to increase durability. Again, this comes at a small sacrifice to accuracy, but could help extend the life of your barrel a few thousand rounds or more. It also comes at a pretty significant cost vs non-CHF barrels.

In our best AR-15 cold hammer forged barrel section, I discuss why I think this isn't worth the cost for most needs and uses.

Barrel Testing

After the manufacturer of your barrel does all of these processes to make it the best it can be, you better hope they test it. The two testing processes to look out for are:

• Magnetic Particle (MP) testing is a nondestructive process that uses magnetic currents to test for cracks or defects in barrels. 
• High-Pressure (HP) testing is high-pressure testing, which is a destructive process.

Personally, I want manufacturers that MP test each individual barrel. I'd recommend ensuring they're NOT just batch tested if you plan to put your life in the hands of a barrel.

Gas Systems

While some AR-15s use a piston system, most use a direct impingement (DI) system. A DI AR-15 directs gas from behind a bullet into the gas tube, which then moves the bolt back, removes the spent casing, and strips a new round off of the magazine into the chamber.

The GIF below illustrates this:

So Why Are We Covering This in a Barrel Guide?

The barrel you purchase will have a gas port drilled into it and sometimes even come with a gas block and gas tube... So you need to decide what gas system length you want.

Gas System Lengths

Gas system length is the distance between the gas block and where the gas tube meets the bolt carrier group's (BCG's) gas key.

The picture (source) below shows:

• Rifle-Length Gas System (12", 20" barrel)
• Mid-Length Gas System (9", 16" barrel)
• Carbine-Length Gas System (7", 16" barrel)

The table below shows general rules for choosing a gas system length. Basically, the only time you're likely to have to make a decision is when you have a 14.5-16" barrel. I always opt for a mid-length system due to it's lighter recoil, which comes as a result of less gas entering the tube. This also reduces wear on your rifles parts. 

Gas System vs Barrel Length Table 

Gas System Length	Barrel Length	Port Distance
Pistol Length	<10 inches	4 inches
Carbine Length	10-18 inches	7 inches
Mid Length	14-20 inches	9 inches
Rifle Length	20+ inches	12 inches

With all of that covered, we're moving onto the best AR-15 Barrels.