When creating or customizing an AR-15, the selection of the proper barrel profile is key. The profile, which determines the shape and size of the barrel, can greatly impact the performance and functionality of the firearm.

Let’s take a look at the different AR-15 barrel profiles available and help you understand the pros and cons of each so you can make an informed decision. From heavier barrel profiles to lightweight pencil barrel profiles, we’ll cover it all.

Whether you’re a competitive shooter, a hunter, or just a hobbyist, this guide will help you choose the perfect barrel profile for your specific needs and goals.

AR Barrel Profiles Explained

The term “barrel profile” refers to the thickness of a barrel on an AR-15 style rifle, such as the Faxon Sentry 16” 5.56 Rifle. Different barrel profiles can impact the performance of the gun in various ways.

Faxon Firearms Sentry 5.56 Rifle product photo

For instance, thinner barrels are lightweight and easy to handle, while thicker barrels provide more stability by adding weight to the front of the gun and can withstand more heat.

It’s essential to consider the trade-offs of different barrel options available in the market when making a choice.

Let’s now look at the different AR-15 barrel profiles to see what makes each one unique.

Gunner Profile

The Gunner profile is a blend of two of the best-performing profiles of all time, Gov’t and Pencil. 

Gunner AR15 Barrel profiles against a white backdrop

Faxon’s Gunner profile combines the durability of the Gov’t profile with the weight savings and maneuverability of the Pencil profile.

The Gunner profile brings the rifle’s balance back towards the shooter’s body, limiting fatigue and allowing for shooting, training, or hunting all day long.

Government/SOCOM Profile

A SOCOM barrel for an AR-15 is designed differently from the standard M4/A2 barrel.

Instead of being consistently thick throughout, it has a thinner section past the gas block and a thicker section near the chamber. In addition, SOCOM barrels often have a slot for attaching a grenade launcher and provide a balance between strength and weight.

If you’re looking for a barrel that can handle sustained shooting while still being lightweight, a SOCOM profile barrel may be a good option for you.

Faxon's SOCOM barrel product photo

Pencil Profile

The pencil barrel is the original profile for the AR-15, typically measuring 0.625 inches in diameter.

It is known for being slim and lightweight, making it easy to carry and handle. However, due to its thinness, it may overheat more quickly during rapid firing, leading to elastic deformation or warping, which can affect reliability and accuracy.

Pencil Ar15 barrel profile y Faxon Firearms

Unlike run-of-the-mill pencil barrels, Faxon Firearms barrels are properly heat-treated and stress-relieved to improve heat resistance and longevity.

The durability of this AR15 barrel profile is ideal for shooters with a light or medium shooting schedule.

AR Barrel Profiles: Finding Your Match

The barrel profile of an AR-15 rifle can greatly affect its overall performance and handling.

The three most common barrel profiles are the Gunner, Government, and Pencil. The Government/SOCOM profile is the thickest and heaviest option, providing the most stability and accuracy but also adding extra weight to the rifle.

The pencil profile is the thinnest and lightest option, making it easier to handle and carry, but sacrificing some stability and accuracy. The government profile is a balance between the two, offering a good compromise between weight and performance.

Ultimately, the choice of barrel profile will depend on the individual’s personal preferences and intended use of the rifle. Therefore, it is important to consider the trade-offs and choose the barrel profile that best suits your needs.

31 COMMENTS

    • 🤣

      “…….the best-performing profiles of all time, Gov’t and Pencil……”
      Sorry, gotta call BS on this.
      Popular and prolific do NOT equal “best performing”.

      Never thought anyone would put “pencil” barrels and “best performing” in the same sentence, but it’s here. Must be true. 🤪

      🤔
      Yes, they perform the best harmonic whipping and best “stringing” of shots due to poor thermal (heat sinking) properties. Also the best at shooting the chrome lining out in no time at all.

      I can’t handle so much best. 🤪
      I choose full profile, Nitride heat treatment (no chrome lining) barrels. Slightly heavier, can take more heat, whipping and stringing are GREATLY reduced. A quality one can shoot well over 50k rounds and still maintain sub MOA groups.

      Facts matter………
      Pencil barrels save weight. PERIOD! End of story.

      • James,

        Yeah, but . . . “performing” is NOT an objective standard; it depends on how you define ‘performance’. The DoD wanted a barrel that was FUNCTIONAL for combat (if far from ideal), but that grunts could hump through the jungle (or mountains, or sand dunes, or rocks) all day.

        EVERY engineering choice is a trade off – weight vs. longevity vs. ‘stiffness’ vs. heat disspation vs. cost vs. a million other things. Ain’t no “perfect answers” in engineering.

        The pencil barrel served as intended. I can argue the trade off, but . . . SOME trade-off was inevitable. And the DoD will usually opt for lower cost, all things considered.

        Not a fan of the pencil barrel, but I’d take one in a pinch. Since I’m a larger guy, I’m less sensitive to weight issues – the difference between a 7 pound gun and an 8 pound gun is negligible.

        I choose barrels for my intended purpose – for precision shooting (or even long-range hunting), I opt for some variation on bull barrel. I do use a modified barrel profile for tactical.

    • The content does seem rather focused on stuff Faxon makes, yeah. Not saying they don’t make nice stuff, of course, just that the focus is pretty conspicuous.

  1. in my experience
    gas system length
    and barrel twist rate
    are more important
    than barrel profile

  2. Since for a long while Criterions were scarce as hen’s teeth my carbines have FN fully chrome lined M4 profile model 20-100046 barrels which I am very satisfied with. As for Faxon watch out for QC. In fact if the seller does not have a free return it is best to ask for a visual bore, crown, etc. inspection prior to shipping, if the seller cannot perform an inspection then find one who will inspect like the good folks at AR15Discounts.
    I use 20″ Faxon Big Gunner barrels on all my AR-308 builds, weight being the primary factor and the barrel profile is sorta USGI M14. Because of the gas port location the Faxon .308 uses a longer gas tube. And if you want to install a detach front sight a PRI 03-750-04 Gas Block is a must. And of course you’ll need a handguard and the only one supposedly Made In America that will work after being shortened 1/8″ is the Hontac 13″ .308 available at AR15Handguard.
    If you want a detach front sight and do not have the tools and skills to do a bunch of set up with the Hontac handguard then go with Aero’s Enhanced upper receiver and their 15″ handguard. The Aero Enhanced .308 upper has a better chance of a handguard mounted front sight being properly aligned with the rear sight.

  3. SOCOM and Government shouldn’t ever be used. Outdated and poor design, having extra metal towards the muzzle exactly where not needed and only adds weight, unbalances the rifle, and can increase point of impact shift when attaching suppressors.

    Pencil barrels are a great choice for light- medium duty. Buy only from premium companies that de-stress the metal. This will ensure better accuracy when the barrel warms up and especially when a suppressor is attached.

    Medium Tapper, the barrel shaped like a triangle is best of all worlds. Good for any fan fare and occasion. Often comes with premium accuracy for less money.

    HBAR heavy profile, recommended for situations of sustained rapid fire or a need for prolonged accuracy in longer strings of fire. Heavy barrels heat up slower and group tighter after multiple shots than thinner barrels.

    • RE: SOCOM and Government shouldn’t ever be used.

      I have never noticed M4 or SOCOM carbine barrels being nose heavy because they are not especially with A-1 or A2 stocks. In fact hammer forged M4 barrels from FN, DD, etc. are hard to beat if one can afford them. As for using really skinny pencil barrels…no way jose.

      Medium weight barrels like Criterion’s Hybrid models are nice. Heavy barrels like Ballastic Advantage are just heavy. Although a good barrel is important overall accuracy and reliability comes from each component interacting properly with each other…and I do mean properly.

      • As if other barrel profiles outside of SOC/GOV can’t be cold hammer forged? There’s a notable handling difference in a rifle upgraded without SOC/GOV profile. Feels lighter and easier to snap from target to target.
        The enemy of accuracy is heat, thicker barrels hold accuracy better with longer strings of fire being slower to heat up.
        Pencil barrels heat up much quicker dwindling accuracy faster but when properly stress relieved this is limited compared to traditional manufacturing methods. This is why the military has been issuing pencil barrel rifles without issue like the SCAR17.
        I thought it would go without saying but apparently not, a good barrel must be matched with a tight and rigid receiver to get it’s full potential, duuuuuh. Who would have thunked.
        All things considered a good barrel slapped in a mil spec rifle will put you about 1 moa, beyond exceptional for anything a person will need it for. If you want sub moa you either have no hands on experience or are highly experienced and know how to get there anyway.

        • RE: “As if other barrel profiles outside of SOC/GOV can’t be cold hammer forged?”

          As if I said or implied that…If you are having trouble acquiring targets and need a pencil to save ounces over a M4 carbine barrel you need to eat your Wheaties and work out more often. There’s light and too light and there is heavy and too heavy. The sweat spot for a carbine lies between too light and too heavy.

      • “There’s light and too light and there is heavy and too heavy. The sweat spot for a carbine lies between too light and too heavy.”

        Too heavy? That can’t be true because someone told me you just eat your Wheaties and workout more!
        Surely you can’t be so keyboard commando you don’t understand weapon balance and target acquisition? Oooff and no longer barreled guns are not Mommy and Daddy guns who get together and have smaller barreled baby guns.

        • cc…you are the pencil dick praising pencil barrels…And paying extra for a hammer forged pencil would be a complete waste of money. I suggest you go with a carbon fiber barrel and consume more fiber because you by your owns words are full of sht and probably in need of a diaper change.

        • cc… And BTW, “The sweat spot for a carbine lies between too light and too heavy.” The keyword is not heavy, etc. The keyword is Carbine. Slow down, you are tripping over your own stupidity. Try again, I’m here to help bozos like you.

    • “Outdated and poor design, having extra metal towards the muzzle exactly where not needed and only adds weight, unbalances the rifle, and can increase point of impact shift when attaching suppressors.”

      soooo….if a little more weight and the balance is acceptable and not going to use a supressor…SOCOM is not an “Outdated and poor design” ?

  4. I might do a SOCOM at some point but pencil isn’t really what I’m interested in. I’m much more inclined toward stainless fluted HBAR’s. 9mm 16 inch barrels with a gradual taper get my attention too. 300AAC is about the only place I might want a gas system less than mid. The whole idea of the AR pistol just doesn’t appeal to me much. A 20lb rifle isn’t required but I don’t mind something with a little heft. Every time I’m ever picked up a Ruger556, it made me feel like I was going to break it.

      • Because I like to build and try new things. I’ve never had one of them. I did say “I might”. But who knows. There are plenty out there that appeals to me more.

  5. Both of my ARs have 20″ HBAR barrels, chosen for accuracy not weight reduction. They are not something I’d care to take hunting, as both guns weigh over 9 lbs without the optic. m(Part of that weight are the Thordsen stocks that make the rifles qualify as “not assault weapons” under California law. This allows me to have a detachable mag and my choice of muzzle device. Most importantly, “assault weapons” have to be registered with the State, cannot change configuration, can only be transported between home and the range or gun smith, and cannot be transferred, sold, or gifted to any other person in the State, but must be taken out of state or delivered to your local sheriff for destruction.

  6. Damn a barrel profile. Within given parameters it doesn’t matter. Neither do flutes. Now rate of twist… Let’s talk about that. I grew up when everything was 55 gr and 1:12. Great accuracy. Poor terminal performance. Oops! Let’s make the bullet heavier. (Remember we already had a round with superior ballistics. Especially for down range performance.) Now we have to increase rate of twist so the heavier .556 will stabilizeze. “Well, does anyone else have any more spit and bailing wire? We’ve lied too many times to tell the truth now.” Even today they’re assing around trying to invent a better mouse trap. Look at the Pentagon and SIG. I have two ARs. Both 1:7 twist. I’ve been trying to find 1:12 replacement barrels. (I have at least 10,000 rds of 55 gr ball and SP). You can not find a quality 1:12″ .223/5.56 barrel. The good news is that Mike found me a very nice Remington 788 carbine in .308 at a gun show in Crystal River yesterday. The bad news is I have to wait 10 days to drive down a pick it up. He and Tori are heading to the Keys for a Jimmy Buffett concert. Welcome to Florida.

  7. Just don’t buy a government profile. The government doesn’t know what they are doing.
    You want some weight at the chamber to handle the heat, and less weight out at the muzzle where it is unwieldy and front-heavy. Leave it to the government to get things completely backwards.

  8. not sure what profile i have. asked for 18″ 1:8. a couple boxes arrived, never opened them, shelved for years. got larue triggers too.
    not really that interested, wanted something.
    i find the whole di thing offputting despite greater accuracy.
    retirement project.

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