The Best AR Barrel Types: Length, Material, and More

Ultimate Guide to AR-15 5.56/.223 Barrels
January 15, 2021 Edited April 24, 2024 20801 view(s)
The Best AR Barrel Types: Length, Material, and More

The barrel on your AR 15 might be more important than you know. AR 15 barrels can determine a lot about your rifle. It optimizes the type of round the gun fires, the purpose, its effective range, durability, and even the legal status your gun occupies. There is a lot to talk about when it comes to barrels, and today, we are going to deep dive into the world of AR 15 barrels. We will talk about the inside, the outside, the length, weight, and beyond. Because there are so many calibers in the AR 15 world, we will have a bit of a focus on the 5.56/223 options. This information can apply to other calibers, but the focus is mostly on the 5.56 variants due to their extreme popularity.


Barrel Lengths

Barrel Length Comparison Chart


The length of your barrel is essential for a few reasons. First and foremost, the length determines the legal status of your firearm. Without going too deep into firearms laws, AR 15 rifles must have barrels at least 16 inches in length to be rifles. Anything shorter results in a short-barreled rifle, which is an NFA firearm, or an AR pistol, or a firearm. That’s the legal line when it comes to barrel lengths.

From a practical perspective, the length of your barrel affects the velocity of your round. The 223 Remington and later the 5.56 NATO is designed to reach peak velocity from a 20-inch barrel. Optimal barrel length varies by round, and cartridges like the 300 Blackout can be optimized from a barrel as short as 9 inches. When choosing a cartridge and barrel, it pays to do some research in which barrel length will optimize the round.

That being said, trimming your barrel length to below optimal length does not render the weapon ineffective. 16-inch barrels are the most popular choice out there for the 5.56 cartridge, and it performs admirably from shorter barrels. The loss of velocity and increase in muzzle flash and concussion are notable, however. The shorter you get, the more blast and loss of velocity you’ll experience.

Longer barrels provide more velocity and generally a more comfortable shooting gun. Shorter barrels allow for more maneuverability and a lighter weight weapon overall. Longer barrels are excellent for long-range shooting, competitions, and hunting. Carbine and shorter length barrels are perfect for home defense and tactical applications. Finding a right balance for your needs is essential, and Bear Creek Arsenal offers barrel lengths from 4 to 24 inches in various calibers for your needs.


Barrel Profiles

Barrel profiles refer to the thick and thin points of a barrel. Light and heavy barrels both have their benefits, and each is purpose-driven for specific rifles and purposes.

Lighter barrels are more ergonomic and more maneuverable. They make the weapon easier to quickly move with, to hold up for more extended periods, and to hike and hump during non gunfighting endeavors. Under sustained fire, they do start to heat up, and accuracy degrades.

A heavier barrel provides a more rigid and stable barrel for greater accuracy. Heavier barrels resist heat and allow for greater precision during sustained fire. The downside is the physics of heavier barrels. More weight slows you down and wears on you more.

Here are the most common ar barrel profiles:


PencilPencil Barrel Profile


Pencil thin barrels, also known as A1 profile, are thin and lightweight barrels. The pencil design is superbly light and perfect for quick snapshots, long hikes, and holding the weapon up for an extended period of time. The Pencil thin barrels aren’t great for long term sustained fire.


Government / M4Government Barrel Profile M4 Barrel Profile


These two profiles are very closely related and differ slightly. [The Government] profile has a thin .625 inch barrel behind the gas block and .750 inch barrel in front of the barrel. This profile is used for the M16A2 barrel type. This barrel type was created to address a barrel bending problem that didn’t occur.The M4 barrel profile is similar but has a thin cut-out in the .750 portion of the barrel to accommodate an M203 grenade launcher. The Government profile is still popular because the M4 profile is still used, although it doesn’t offer much advantage besides extra barrel weight helping to deal with recoil.


Heavy BarrelHeavy Barrel Profile


Heavy barrels are designed to defeat the heat and enhance accuracy at the cost of more weight. Heavy barrels are popular on rifles built for extreme marksmanship and consistent fire. Heavy profiles can vary, but they are typically thick until near the barrel's end, where they taper towards the thinner side for balance. Heavy barrels are also popular with ultra-short AR 15 barrels. Weight is the primary downside of this profile.


FlutedFluted Heavy BarrelDiamond Fluted Heavy Barrel


Fluting a barrel involves strategically removing material in areas where it is not needed to reduce weight while maintaining a rigid barrel. A fluted barrel can often deliver benefits similar to, but not equal to, a heavy barrel without the weight. [See our blog post about the benefits of fluted barrels.]


Barrel Materials

41404140 Steel Barrel


4140 is excellent barrel steel that’s common in budget barrels. This barrel type is more than capable of acceptable accuracy with suitable ammunition. Match grade, they are not, but they are satisfactory for most shooting endeavors.


41504150 Steel AR 15 Barrel


4150 contains slightly more carbon than 4140, and that little extra carbon makes 4150 barrels a little more robust for a longer barrel life and a little more accurate.


Chromoly Vanadium 4150Chromoly Vanadium 4150 BCA


Chromoly Vanadium sounds like a synth-pop band, but alas, it’s a steel that delivers an excellent combination of strength and precision. It outperforms 4140 and standard 4150 at a slightly higher cost. This is the steel used in Colt M4 military rifles, and it’s well-proven. [Bear Creek Arsenal uses Chromoly Vanadium 4150 Steel in all their AR barrels with parkerized and black nitride finishes.]


416R StainlessBear Creek Arsenal Stainless Steel AR 15 Barrel


If your goal is to build an absurdly accurate AR 15, then 416R is the steel to go with. Stainless steel enhances accuracy and resists heat better than other standard steels. Most shooters won’t need this type of barrel. 416R stainless steel barrels are designed for sub-MOA accuracy with match grade ammo, and their high price reflects that. [416R Stainless Steel is used in all of BCA’s stainless steel barrels.]


Twist Rates

Twist rates are an interesting conversation to have, but you must realize exactly what we are discussing before we do. The twist rate refers to the rifling on the inside of the barrel. Rifling is a series of lands and grooves that rotate the projectile as it travels down the barrel. This rifling imparts spin on the projectile and stabilizes the bullet throughout its travel.

Twist rate is in reference to how often a projectile makes a complete rotation inside the barrel. Twist rate is usually expressed as a number like 1:7, 1:8, 1:12, and anything in-between, below, and beyond. The one stands for one complete rotation, the number after the one is how inches it requires for the round to make a complete rotation. So with a 1:8 twist rate, it takes 8 inches of barrel for the projectile to make a full rotation. The smaller the number on the right is, the faster the twist rate. 1:7 is faster than 1:12, for example.

Different twist rates exist not just for different calibers but for different bullet sizes. Stabilization is based on bullet length more than weight. Longer bullets are typically heavier bullets are require a fast twist rate to stabilize. In the AR 15 world, the most common heavyweight projectile is 77 grains. A 77 grain round is best stabilized by a 1:7 twist rate.

Lighter rounds like 55-grain spitzers can be stabilized by something as slow as a 1:12, but those are relatively uncommon. Most AR owners would be well served with anything in 1:7, 1:8, or 1:9 category. If budget based bulk ammo is your primary choice, then the 1:9 twist rate is quite versatile.

When choosing a barrel, consider your specific caliber, as well as your intended projectile weight.


Rifling Type

Twist rates are one part of rifling to consider, but a second part is how the rifling is applied. There are two common types of rifling application, cut rifling and button rifling.


Cut Rifling

Cut Rifling Machine


Cut rifling is a cool old school means to rifle a barrel. Cut rifling requires each individual cut to be applied by a single cutter. This slow process is incredibly measured and very precise. The end result is the forming of a supremely accurate rifle. Cut rifling is most commonly used in rifles designed to achieve a sub-MOA. It’s a lengthy, time-consuming process that demands a premium.


Button Rifling

Button Rifling Machine


Button rifling is the most common type of rifling applied to modern rifles. It’s quick and very efficient for mass production and produces perfectly acceptable and downright good accuracy. A sizeable hydraulic barrel drives a mandrel through the barrel and leaves a rifled barrel behind. Button rifling works well for the vast majority of rifles.


Cold Hammer Forged

Cold Hammer Forged Machine


Cold hammer-forged barrels are created when a mandrel with the reverse imprint of the barrel’s rifling is beaten into a barrel blank. The hammers beat the heck out of the barrel around the mandrel. This forges the rifling on the inside of the barrel. The is taken off the mandrel, and your barrel is complete. Cold hammer-forged barrels are incredibly durable and provide an excellent degree of accuracy and durability under sustained fire.


Barrel Treatments

Barrel treatment is the application applied to the inside and outside of the barrel. Barrels are exposed to intense heat and pressure and are prime candidates for rust. A good treatment helps expand barrel life and defeat common barrel ailments.


Chrome LiningChrome Lined Barrel


Chrome lining is an internal bore coating that is applied to the rifling, the chamber, and the bore. Chrome lining resists rust and ensures the inner barrel is nice and hard. Chrome lining remains a popular choice for manufacturers and is well proven.


NitrideBlack Nitride Finish AR-15 Barrel


Nitride treatment is a process of case hardening the barrel that hardens the steel and lends itself well to an incredibly durable barrel. To achieve this, the barrels are dipped into a combination of nitrogen, oxygen, and carbon that is heated to 1,600 degrees. This binds the chemicals to the steel. It also turns the steel a matte black that resists rust and common abrasions. Melonite is a commercial brand name for nitriding a barrel.


ParkerizedAR-15 Barrel Parkerized Finish


Parkerized is a commercial term for a barrel treatment that’s become popular enough that the name parkerized has become synonymous with manganese phosphate. Parkerizing uses a manganese element to create a treatment over the steel of the barrel. At the same time, it doesn’t make the steel as strong as nitride coating but is more affordable and more comfortable to apply.


A Barrel of Barrels

There is no perfect barrel choice that will work with every AR-type rifle. It’s a silly idea that there could be a perfect barrel for every AR rifle, pistol, or firearm. There are too many different designs and types to ever make that true.

That’s a good thing, by the way. This allows us to customize our AR to a specific task, and that’s an uncommon virtue for firearms. You can have a half dozen ARs designed for different purposes, and one of the biggest deciding factors in their purpose is their barrel lengths. Choosing the right barrel is a big choice, and hopefully, what we’ve discussed here today will lead you to the right barrel for your gun.


Bear Creek ARsenal Barrels


[We'd like to extend a huge thank you to Travis Pike for his hard work on this article. Check out our other helpful content like our complete guide to AR-15 Calibers and 5.56 vs 7.62x39!]


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January 20, 2021
This was an excellent read!! thanks
January 20, 2021
bear creek has good products..... people dont know that most of the guns being made are people that worked for colt or other high end firearm manufactures.and i read a article they were laid off,,,so how about that thanks bear creek great products
Randy Siegler
January 20, 2021
Will you all ever have the 6.8 SPC II barrel back in stock. Right now with the ammo shortage regarding most AR15 related ammunition- the 6.8 SPC II ammo is still available from a few different ammunition distributors. I have everything available to build an AR15 in 6.8 SPC II with the exception of the barrel. There are other folks that I am aware of that have previously purchased BCA barrels that are wondering/waiting if BCA will resume sale of the 6.8 SPC II barrel. THANK YOU Bear Creek Arsenal.
January 20, 2021
Sorry Randy , there are no plans to bring back the 6.8 SPC II barrel at this time. We recommend the 6.5 Grendel in its place, its flatter trajectory should make it an easy substitute.
Cory A Best
January 21, 2021
Very nice and informative article without getting too deep into the weeds. Thanks Travis! ????
Mike Liebe
January 21, 2021
This was an awesome and very educational article! Thank you
Todd Vuckovich
January 22, 2021
Good job excellent format. Depth of delivery has cleared many questions on such a broad subject .. Thank you
Tim Croyle
January 28, 2021
Love the 6.5 grendel 20” stainless fluted barrel it is super accurate.
February 14, 2021
This was a great read, I learned alot
Ray Hammer
February 18, 2021
Is there any reason why you can't make some barrels the DO NOT weight 20 pounds? I can't see that putting the Mil spec contour on 762x39 or 350 legend, will hurt anything in the 16 and even 18 inch lengths. it is very hard to use certain mounts on closer to the receiver because the barrel is too big. I would rather not have to spend more money to get a barrel that is a lot lighter and slimmer. My customers are not even looking at BCA uppers anymore they are to heavy.
February 19, 2021
we have found the barrel’s level of accuracy increases exponentially through heavy barrels which is why our longer options are typically in this profile. We want to provide everyone with the most accurate barrel we can. Hope this is of some help.
Robert Lott
March 15, 2021
Just got in my new upper,10.5" 7.62x39 broke in as bca suggested shooting Wolfe and Tula all in moa thanks.I love my pistols . By the way a good read yes it was .
July 13, 2021
Thanks Travis! Great short explanation on different barrels, materials, and treatments. I'm kind of new to AR's, and always research what I'm interested in. Sometimes though, if you get excited about something, you attempt to explain it to the uninformed, and get crickets, and blank stares. Next you need to post an article on different powders, bullet weights, drag coefficients, primers, case crimps, etc. ????
Sam Pond
October 1, 2021
First of all this blog is great info but it does leave me with one question I just ordered and waiting delivery of an 18" bear claw 223 wylde complete upper black nitride finish in the description it says 416r stainless steel but up above in this it says bca uses chromoly 4150 in all their pakerized and black nitride finishes so this is a bit confusing on what I exactly bought any clarity on this would be greatly appreciated i am looking forward to receiving my upper to finish my very first ar build and from all research I've done bca is highly praised and I'm looking forward to more business with you in the future
John B.
February 18, 2022
Interesting, enjoyably presented material, and useful. After reading and later using this for reference, I believe I can go speak rather smartly when purchasing a longer barrel for my AR pistol if the 12” barrel becomes illegal in August. Thank you.
May 14, 2022
Thanks! I learned a lot today.
J. Gray
May 29, 2022
Great Article. But 1 thing weighs heavily on my heart. You left out 2 of the best barrel lengths in the picture. The 11.5" and 12.5"
Larry Holton
August 7, 2022
Do you ever produce a reasonable barrel? First barrel of yours couldn't stay on a 12-in piece of paper at 100 m. Got rid of the entire upper. Bought another barrel because it's the only one I can find at the time and it's no better than 3 moa is the best it'll do it 100 m. Fouls very fast and what accuracy there is goes away at that time.
July 10, 2023
I have not had your bad luck with their barrels. The .243 winchester barrel I have shot 3/8" ans 1/2" groups at 100 yards with factory ammo. 100 grain federal. The .308 shoots good too. Under 1 moa. Had a under gassed. 243 upper. They made it right. Runs good. 12 inch piece of paper. Glad I did not get your barrel. I think bear creek products are a great value. Yes fast production all computerized but that is how they keep the price down. That is business. Might get a lemon here and there but they always make it right. I think bear creek is a quality product for the price. Very durable for the price. Talk to bear creek I know they will make it right.
Mark Chandler
December 28, 2022
Way to break it down Teavis
Dave R Few
February 28, 2023
Excellent barrel discussion. Very informative for both novice and experienced gun buffs
John L. Wilson
September 19, 2023
Your website has a wealth of knowledge, I have three of you action on my to get list. Question will you be having anymore 22" 416 barrel in the future in 308 or 6.5 Creedmoor. I have a side eject 300 B my brother got me before he past last, I love the gun and the action style. Great Job J.W.
Joseph peri
October 25, 2023
Can u make a 25/06 20”ss fluted barrel n if so approx cost
Mike Harendt
October 25, 2023
Enjoyed this informative article.
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