The Best 300 Blackout Barrels for Driving Fat AR Rounds

300 Blackout is one of the best alternatives to .223/5.56mm for an AR. A 300BLK rifle is a great suppressor host. 300 Blackout hits hard at (relatively) short ranges. And it fits in 5.56mm magazines. In short, a 300 AAC rifle is a great rifle.

And it’s an AR pattern rifle. So you can build a 300BLK rifle yourself, like a Lego set. So, it’s totally reasonable to be here looking for the best 300 Blackout barrels for your 300BLK blaster.

Unsurprisingly, most of the best .223/5.56mm barrel manufacturers also make some of the best 300 Blackout barrels. Our collection of the best 300 Blackout barrels bears this out.

Ballistic Advantage Modern Series
  • 4150 chromoly vanadium steel is super durable and long lasting.
  • Precise enough to produce sub-MOA groups at 100 yards.
  • QPQ coated for incredible corrosion resistance and great aesthetics.

SPOILER—if you just want to know which 300 Blackout barrels came out on top, the Ballistic Advantage Modern Series .300 AR Rifle Barrels are easily the overall best 300 Blackout barrels you can get, all things considered.

If you’re looking for something different, keep reading. We’ve got all the best 300 Blackout barrels on the internet lined up for you to shoot out.

Top 300 Blackout Barrels on the Market Today

The Best 300 Blackout Barrels Reviews - Barrels for Bigger Rounds

The overall best 300 blackout barrels are up for review first. The best 300BLK barrels from each category will be presented in order of price.

The best barrels for your budget are in the first reviews.

The best barrels for absolute performance are near the end.

Read the reviews that cover the barrels that match the dollars in your gun budget.

1. Ballistic Advantage Modern Series .300 AR Rifle Barrel - Overall Best 300 Blackout Barrels

Ballistic Advantage barrels are easily some of the best rifle barrels that you can get. The price to performance ratio is incredible. That’s why the Ballistic Advantage Modern Series .300 AR Rifle Barrels are the overall best 300 Blackout barrels.

These are super affordable barrels. But they’re also very well made.

These barrels are made from 4150 chromoly vanadium steel. It’s a super durable steel that lasts for a very long time.

And, although 4150 steel isn’t quite as precise as stainless steel, these barrels still shoot sub-MOA groups at 100 yards. So these barrels are precise enough for any type of shooting.

On the outside, these barrels are QPQ coated. It’s a superb finish that offers excellent corrosion resistance. And it has a great semi-matte look. It’s a much better coating than the standard mil-spec phosphate finish.

It’s nothing special. But these barrels have M4 feed ramps to ensure reliable feeding.

The only real struggle with these barrels is that they have a pistol length gas system. There’s nothing wrong with a pistol length gas system. It’s a very reliable gas system because the dwell time is huge.

However, a pistol length gas system gives you a slightly sharper recoil impulse than a carbine or mid-length gas system. And, if you’re using a longer barrel—like a 16 inch barrel—you’ll get plenty of dwell time from a carbine or mid-length gas system.

It would be nice if these barrels offered a longer gas system for the longer lengths, rather than just sticking with the pistol length gas system for every barrel length.

But that’s a minor issue. And using a pistol length gas system helps avoid reliability issues that you can experience with a longer gas system that has less dwell time.

Even though there aren’t many gas system length options, these are still excellent 300 Blackout barrels that you can get for a ridiculously good price. You can’t go wrong.

Pros

  • 4150 chromoly vanadium steel is super durable and long lasting.
  • Precise enough to produce sub-MOA groups at 100 yards.
  • QPQ coated for incredible corrosion resistance and great aesthetics.
  • M4 feed ramps deliver reliable feeding.
  • Pistol length gas system gives you tons of dwell time for reliable cycling.

Cons

  • 4150 steel is slightly less precise than stainless steel.
  • Only available with a pistol length gas system, regardless of barrel length.

2. Faxon Firearms 300 Gunner Rifle Barrel - Budget 300 Blackout Barrels

Faxon Firearms is another barrel manufacturer that produces excellent rifle barrels that are surprisingly well-priced. So the Faxon Firearms 300 Gunner Rifle Barrel is a perfect barrel for anyone who needs an affordable barrel, without compromising performance.

First, these barrels are constructed from 416R stainless steel. Stainless steel produces excellent precision and wears evenly. So you get a very precise barrel that stays precise until the end of its life.

On the outside, these barrels are coated in black nitride. This finish is super corrosion resistant. And it’s super smooth and looks really cool. It’s one of my favorite finishes for AR components.

But the big deal with these barrels is the profile.

These barrels are made with Faxon’s Gunner Profile. It’s a hybrid profile that combines a pencil profile with a government profile to maximize precision and heat resistance, without the extra weight and awkward balance of a government profile.

Essentially, this barrel has a medium profile up to the gas block, then a pencil profile in front of the gas block. It’s a really brilliant profile design that’s precise, easy to handle, and relatively lightweight. Pretty much the best of all worlds.

There’s not much to complain about on these barrels. But it is a bit unfortunate that Faxon doesn’t manufacture these barrels in some of the intermediate lengths. You can get 10.5 and shorter. Or you can get 16 inches.

I’d like an 11.5 or 12.5 option. But that’s not a huge deal. There are other manufacturers that offer barrels in those intermediate lengths. If you need the most performance-per-dollar, these Faxon Firearms barrels will do the trick.

Pros

  • Manufactured from 416R stainless steel.
  • Black nitride finish is super durable and looks great.
  • Gunner profile offers the precision of a government profile barrel, in a lighter package with less swing weight.
  • 16-inch model is equipped with a carbine length gas system.

Cons

  • No 11.5 or 12.5 inch variants available.

3. Rainier Arms Select 300BLK Barrel - 300 Blackout SBR Barrels

The Rainier Arms Select barrels are an amazing option for any caliber. So the Rainier Arms Select 300BLK Barrels are excellent 300BLK barrels. Period.

The default length is 8 inches. If you’d like a more traditional SBR length, you can get the Rainier Arms Select 300BLK Barrel 10.7” barrel.

In either case, you get a stainless steel barrel with a super durable nitride finish. The finish has a matte aesthetic, because it’s super thick and durable.

The finish still looks really good, even if it looks more like a phosphate finish than other manufacturers’ finishes.

Also, the receiver extension has a polished finish for easier installation and a better receiver fit.

However, the main features are in the contour and rifling.

First, these barrels use a proprietary medium contour that’s more precise than a government profile barrel, but weighs about the same. And the swing weight is lower, because most of the metal is near the chamber, where most of the pressure and heat buildup occurs.

In short, you get more precision and heat resistance without any additional weight.

Internally, these barrels use polygonal rifling.

Polygonal rifling is slightly less precise than traditional rifling. But these barrels still shoot sub-MOA groups at 100 yards.

However, polygonal rifling produces less bullet deformation and a better seal with the bore. This produces higher muzzle velocitiesThis is actually a great feature, since you’re shooting a heavy, relatively slow moving bullet from a short barrel. You want as much velocity as you can get.

And these barrels produce the most possible muzzle velocity for the barrel length.

Ultimately, that’s why these are great barrels for a 300BLK rifle with a short barrel. You’ll get the most ballistic performance from the shortest possible carbine.

And these Rainier Arms barrels are super affordable. You get a super well made barrel that offers excellent performance, for a really reasonable price. It’s a hard deal to turn down.

Pros

  • Stainless steel construction produces excellent precision.
  • Medium contour offers more precision and heat buildup, with the same weight as a government profile barrel.
  • Nitride finish is super corrosion and wear resistant.
  • Polished receiver extension ensures easy installation with a better receiver fit.
  • Polygonal rifling offers the most possible muzzle velocity for the barrel length.

Cons

  • Polygonal rifling produces slightly less precision than traditional rifling, although these barrels still shoot sub-MOA groups.

4. CMMG AR-15/M16 300 BLK Barrels - Precision 300 Blackout Barrels

The CMMG AR-15/M16 300 BLK Barrels are built for enhanced precision, with less focus on being lightweight.

Interestingly, these barrels are constructed from 4150 chromoly vanadium steel. It’s more durable and longer lasting than stainless steel. But also a tad less precise.

However, these barrels use a full profile. These aren’t quite bull barrels. But even the thinnest section of these barrels is thicker than the thinnest section of a government profile barrel. And the thicker profile goes all the way to the muzzle.

In short, these barrels use a sturdier profile to enhance the precision, with a more durable steel to enhance the lifespan. So you get a super precise barrel that lasts a super long time.

Unfortunately, that means that these barrels are heavier than barrels that utilize a thinner profile.

Then, these barrels are finished in CMMG’s proprietary black nitride finish. The finish is highly corrosion and wear resistant. And it has a matte appearance. It looks good and holds up well. What more can you ask for?

Now, these barrels are a bit pricey. But, if you’re building a precision 300 Blackout rifle, you’re probably prepared to pay for that precision. And—for a precision barrel—these barrels are very reasonably priced.

Pros

  • 4150 chromoly vanadium steel is tough and lasts a long time.
  • Full profile is more precise and heat resistant than a government or medium profile barrel.
  • Protected by CMMG’s proprietary black nitride finish, which is super corrosion and wear resistant.
  • 16-inch model is fitted with a carbine length gas system to smooth out the recoil impulse.

Cons

  • A bit heavier than a government profile barrel.
  • A tad pricey.

5. ODIN Works 300 Blackout Medium Profile Barrel - 300 Blackout Barrels for Adjustable Gas Systems

One of the toughest things to get right with a 300 Blackout rifle is the gas system, especially if you plan on running a suppressor. The ODIN Works 300 Blackout Medium Profile Barrel helps you avoid gas system issues, and run your rifle with or without a suppressor without overgassing.

First, the standard stuff:

This is a 416R stainless steel barrel. It’s a very precise steel that retains its precision through its life. And this barrel uses a medium profile for the best precision from the lightest barrel possible.

Then, the finish is a super durable, highly polished black nitride finish.

Overall, the precision and durability are top notch.

However, the main thing about these barrels is that they come with an adjustable gas block. And the gas port is drilled out to accommodate a wide range of gas settings.

That way you can tune your gas system to get reliable operation with or without a suppressor. This enables you to ensure that your rifle runs reliably, without excessive wear on the internal components.

A tunable gas system is a huge asset for 300BLK rifles, since they make such good suppressor hosts. Even though this ODIN Works barrel might be a tad expensive, it will save you a ton of headache. And it will save you money in the long run, since you’ll end up replacing fewer parts.

If you’re planning on running a suppressor at all, this is the barrel to get.

Pros

  • 416R stainless steel offers top notch precision throughout its lifespan.
  • Durable, highly polished black nitride finish.
  • Medium contour offer the best middle ground between precision and low weight.
  • Includes a tunable gas block enables you to easily resolve gas system issues and ensure that your rifle isn’t overgassed.

Cons

  • Expensive.

Shooting Out the Barrels

300 Blackout rifles are super versatile rifles that make great suppressor hosts and defensive guns. But, as with any caliber, your barrel is an incredibly important component. So it’s important to get the best 300 Blackout barrel for your rifle.

Ballistic Advantage Modern Series

If you want a great 300 Blackout rifle without any headache, just get one of the Ballistic Advantage Modern Series .300 AR Rifle Barrels. They’re excellent barrels that are also incredibly well-priced. You can’t go wrong.

It’s time to finish that 300 Blackout build, or just upgrade your rifle’s performance. Get a better barrel. Get a better rifle.