Best 300 Blackout Barrel

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The 300 Blackout is an efficient cartridge that excels in several shooting applications like hunting or precision shooting. If you’re building a custom 300 BLK rifle, choosing the best 300 Blackout barrel is critical. We’ll show you our selection process.

How to Choose the Best 300 Blackout Barrel

Barrel Length

300 Blackout barrels come in two configurations: pistol-length barrels (6″ to 12″ typically) and carbine-length barrels (16.5+” long).

The longer the barrel, the greater the muzzle velocity and more accurate your rifle is. But take note that firearms with longer barrels are heavier. It means you’d have difficulty maneuvering your rifle due to extra length and weight, especially if you have short arms or when shooting in tight conditions.

Also, most 300 AAC Blackout factory ammo burns powder efficiently in barrels 9 to 10 inches long, therefore the improvement in accuracy isn’t that noticeable beyond that. So think long and hard if you really need a barrel that’s longer than that or if it’s practical.

If you want a pistol-length barrel with a standard-shouldered stock, you need to secure a permit from the ATF so you can own and shoot it. And, the ATF is currently pushing for tighter regulations on formerly pistol braces too.

Best Barrel Length for Home Defense

Aside from its effect on accuracy, your intended application is also a huge consideration when choosing barrel length.

If you need your 300 BLK for home defense, where your hallway might resemble a narrow bowling alley, a shorter barrel is your best buddy. When you’re trying to navigate your living room at 2 AM, a shorter barrel (typically around 8 to 9 inches) is ideal. This barrel length turns the .300 Blackout into a nimble, easy-to-maneuver tool that won’t have you knocking over your grandma’s vase while investigating that suspicious noise.

Best Barrel Length for Hunting

For hunting, it’s a whole different ball game. Out in the wild, where your targets are more than just a few yards away, a longer barrel (about 16 inches) is the name of the game. With this length, you get more precision, better velocity, and energy, making sure that your prey doesn’t turn into the one that got away.

Best Barrel Length for Suppressed 300 Blackout

If you’ll be installing a suppressor that’s 6 inches long, a barrel that’s 8 to 10 inches long is suitable. This will result in a total barrel length of 14 to 16 inches which will deliver increased accuracy.

Whether you’re defending your home or hunting in the woods, remember, size – or in this case, length – does matter!

Weight

A heavy barrel equals a heavy rifle. Think about this when choosing your 300 Blackout barrel, especially if you’ll be mounting other gun accessories that can add to your rifle’s overall weight. A heavy rifle will help dissipate heat faster from sustained fire and can handle recoil better. But it will also be difficult to carry especially if you have to run around.

Twist Rate

Your barrel’s twist rate should be able to stabilize your bullets at all of the ranges you expect to engage targets.

The twist rate indicates how much a bullet will spin for every full rifling rotation. Subsonic loads have heavier bullets weighing 225 grains and above so they’ll perform better with 1:8 twist rate. Supersonic loads have lighter projectiles (85 to 125 grains) so a 1:7 twist rate will be more efficient.

If you also want to upgrade your buffer assembly, you need the best 300 Blackout buffer spring.

Profile

The barrel’s profile or contour immensely affects the rifle’s overall performance. A heavily contoured barrel offers increased accuracy and faster heat dissipation. There are three types of barrel profiles:

• Pencil barrels – are affordable but less durable and thinner.
• SOCOM barrels – fairly durable barrels that offer medium contouring. 
• Government barrels – are extremely durable but are very heavy.

Rifling

As for rifling, you can choose between button rifled, 5R rifle, and cut rifled barrels. Despite being more accurate, cut and 5R rifling can mostly be found in premium barrels and are more expensive. Button-rifled barrels are more common because they’re easier to manufacture and are more affordable.

Material Construction

A high-quality barrel is constructed from one of these; 4140 hardened steel, 4150 steel, 416 Stainless Steel, and 416R Stainless steel.

If your priority is resistance from extreme temperatures, corrosion, and rust, go with a stainless steel barrel. But if you want your barrels rock-solid, you can’t go wrong with chromium-molybdenum-vanadium alloys like the 4140 and the 4150. These alloys are tougher than normal carbon steel because they undergo thermal treatment to obtain stronger physical properties.

You might also want to consider a threaded barrel for when you decide on adding a suppressor.

6 Best .300 Blackout Barrels