Exploring the Different Types of AR-15 Barrels

As you delve into the intricate world of planning your next AR build, it’s easy to fall into the trap of simply snagging any barrel that ticks off the basic requirements—correct caliber and desired length. Yet, it’s critical to recognize that the landscape of barrels is wide and varied, and these variations are far from trivial. We’ll dissect AR-15 barrel types and materials in this commentary to enrich the insightfulness of your AR-15 construction adventure.

Different Types

Let’s unpack the 3 principal barrel types differentiated by their rifling genesis—encompassing cut rifling, button rifling, and those birthed by the cold hammer forging process. It’s pivotal to acquaint yourself with these techniques, as they bear significant bearing on your barrel’s persona Thermal Monocular.

Cold Hammer Forged (CHF)

Generally dubbed ‘CHF,’ cold hammer forged barrels are conceived through an arduous process entailing a barrel blank sheathing a rifling-etched mandrel. This pair is thrust into a forge where quartets of hammers diligently pound the blank, giving birth to the barrel’s rifling. Here’s a comparative glimpse of CHF barrel virtues and drawbacks:

Pros:

• The forging journey endows them with enhanced heat fortitude.
• Prodigal round counts translate to commendably extended lifespan.
• Often perceived as a hallmark of excellence, typically boasting preeminent precision.

Cons:

• Potential discrepancies in accuracy contingent on the manufacturer’s repute.

Cut-Rifled

An artifact of historic rifling methodology now executed with contemporary machinations. Cut-rifled barrels come to life as a hook instrument, systematically drawn through a gyrating barrel blank, meticulously carving out rifling in a finely tuned twist rate. The hook must forge a path multiple times to consummate the process.

Pros:

• Unwavering consistency in rifling twist.
• Stringent dimensional exactness.
• Minimally stressful on the barrel during creation.
• Stellar for marksmanship endeavors, offering peak accuracy (Sub MOA pots).

Cons:

• A rather costly and time-intense procedure.
• Imperfect for large-scale replication.

Button-Rifled

Manufacturing at the speed of lightning characterizes button rifling, enabling the mass creation of barrels. In this modality, a button composed of exceedingly durable tungsten carbide, impregnated with rifling’s negative imprint, sculpts the rifling within barrel bores. Manufacturers may opt to either nudge or tow the button through the barrel blank.

Pros:

• Singular passage requirement makes for an expedient process.
• Light on the wallet and ubiquitously procurable.
• Capable of churning out barrels with commendable precision.

Cons:

• Post-rifling stress-relief is obligatory.
• A fraction of the output may betray a bargain-bin quality.

Dive into these details with gusto, and allow this information to shape your AR-15 build with wisdom and precision; may your choices reflect both knowledge and skill.

Which AR-15 Barrel Type Is Best?

When the sun sets and the range falls quiet, every sharpshooter worth their salt has a preferred make of barrel—they’ll stand by it, through thick and thin. Diverse preferences abound: one marksman might be all-in on CHF barrels, while another puts their trust exclusively in the precise grooves of a cut or button rifled barrel. Now, overlooking the rarities in the barrel world, such as TRIARC’s track rifling—which we’ve sidestepped in our discussion here—each rifling style presents a unique blend of pros and cons.

Venture into the territory of the commonplace AR-15 barrel, and you’ll likely encounter the button rifled variety—affordability and ubiquity make them the go-to option. Even those barrels that are the butt of some “budget-friendly” jesting can tough it out for an impressive ten thousand rounds. That’s a tally most gun aficionados won’t even dream of reaching in their shooting careers.

On the topic of cut rifled barrels, you’ll find a cluster of precision aficionados who’ll tout them as the crème de la crème, outliving their button rifled counterparts.

Achieving such longevity isn’t a Herculean feat, especially when high-caliber cold hammer forged barrels are hitting the scene, brandishing lifespans that start at a hefty 20,000 rounds, with some legends clocking in at a staggering 30k.

That said, it’s not all doom and gloom for button rifled barrels on the accuracy front—some are indeed on par in precision. Their Achilles’ heel? They potentially bow out earlier than their cut rifled or cold hammer forged brethren. To put it bluntly, the rifling method is just one variable—the barrel’s craftsmanship from the manufacturer plays a pivotal role.

AR-15 Barrel Materials Breakdown

Carbon

Enter the arena of carbon steels, or low alloy steels if we’re being pedantic. Peeling back the layers, we’re talking about a cocktail of elements paired with carbon and iron. Stir these together in an electric or oxygen furnace until they melt down, then forge them into unwavering unity. 

Stainless Steel

And for the stainless steel, or SS barrels—these are the gleaming spectacles jutting from AR15 handguards and rails. Gone are the days when I presumed them a fashion faux pas of the aged marksman. Beyond their shimmer lies a practical rationale—stainless steel brings durability to the table, warding off corrosion like a champ, which can’t be ignored, especially if your shooting expeditions involve humidity or your barrel is prone to a good drenching. Mind you, though the 400 series plays tough against rust, neglect their care, and they’ll show their displeasure with rust.

The Cream of the Barrel Crop?

Laying it all bare, with the juggernaut of modern technology at our disposal and a couple of decades worth of advances in barrel manufacture, our two cents rest firmly on the 4150 CMV. It’s a veritable standout for AR15 barrels and, frankly, the whole AR series. But here’s the kicker—the real magic happens with what coats the barrel, which is the next treasure we’ll unearth.

AR-15 Barrel Finishes

When you’re delving into the realm of AR-15 barrels, there’s one facet that cannot be overstated—the finish. This begs the question, how do you choose an appropriate coating for your AR? Which finish takes the crown? And are there any that you should maybe give a wide berth?

Parkerizing

It’s essentially analogous to phosphating; it’s a method that leaves firearm components with a protective coat. Back in the World War II era, this process was frequently referred to as “blueing.” However, times have evolved and so have finishing rigorousness, propelled by military standards. What we’re presented with these days is manganese phosphate, a robust treatment that’s garnered the descriptor “parkerized” for barrels.

The term “parkerizing” hails from a bygone company, specifically the Parker Rust-Proof Phosphating Company, which provided phosphating solutions from 1915 all the way through the 1950s.

There’s a prevailing notion that anything that’s up to snuff for the military’s rigors should ostensibly be a cinch for civilian applications. Manganese phosphate is a sterling choice for AR-15 barrels, yielding a robust matte finish that’s non-reflective and durable—not to mention its proficient knack for clinging to oil.

Chrome Lined

Now, shifting our focus to Chrome Lined barrels. These barrels are renowned for their resilience against the vagaries of weather and an elevated number of rounds fired. It’s critical to grasp that “chrome lined” pertains to the internal bore lining and isn’t a reference to the outer surface.

AR rifle barrels typically come in two flavors: either chrome lined within the bore itself or, on the flip side, barrels sans internal chrome lining which are distinguished as “match grade” and are mostly crafted from stainless steel.

Nitride Coated

Switching gears to Nitride Coated – as of 2021, this finish seems to be all the rage, sweeping across quality, type, and brand spectrums. What’s the draw? Well, subjecting an AR rifle barrel to nitriding vastly escalates its resistance to corrosion, outperforming even chrome lined barrels in this respect while retaining the bore’s shaping prowess.

It’s key to spotlight that nitride coating isn’t just for the barrel’s exterior; it embraces the bore too, with the Achilles heel of potentially succumbing to excessive heat with less grace than its chrome lined counterparts, occasionally leading to premature failure if taken beyond its thermal limits.

To its credit, black nitride is also a real looker. Given its hardness, it acts as a formidable protectant, meaning random drops, scuffs, or scratches essentially become non-issues.

And when we look at the process from a manufacturing angle, nitriding is relatively more straightforward and economical, translating to savings for both producer and purchaser. It’s not uncommon to see firearm aficionados taking their stainless steel barrels to get that extra nip of nitride coating just for an added protective shield.

Twist Rate

And finally, let’s touch on Twist Rate. Picture the iconic start of a 007 flick—James Bond in the sights, the screen spiraling with lines. Those lines represent the twist rate of a barrel. The AR-15 commonly sees twist rates such as 1:7, 1:8, and 1:9, reflecting how often a bullet completes a spin for every seven, eight, or nine inches it travels downrange. Getting the gist?

This is intricately linked with why extended barrels might pump out bullets with more gusto—they have more room to spin up before they embark on their trajectory. When you’re pondering barrel twist rates and lengths, it’s crucial to align your choice with the ammo you’ve got in your arsenal.

Mismatch them? Well, you won’t witness precise perforations on your targets, but rather “keyholing.” That’s when your bullet isn’t spiraling gracefully like a well-thrown pigskin; instead, it’s clumsy, tumbling through the air, which can seriously undermine its impact efficiency. And obviously, that’s a scenario best avoided.