The .300 Blackout barrel delivers firepower and accuracy comparable to longer barrels. When you pair the barrel with .300 Blackout ammo, you get an easy-to-carry gun that spits rounds capable of penetrating heavy barriers. Even better, the .300 Blackout barrel comes in various lengths, allowing you to pick a length that best fits your needs.

Keep reading to discover the best barrel length for .300 Blackout for different shooting scenarios. If you already have a favorite .300 Blackout barrel length and are in the market to buy one, check out our selection of premium .300 Blackout barrels.

The Best Overall .300 Blackout Barrel Length: 9 to 10 Inches

The best barrel length for .300 Blackout depends on how you intend on using your gun. Shorter barrels are ideal if you want a concealable and easy-to-carry gun, while a longer barrel is the best choice for optimal accuracy.

However, if you want a .300 Blackout barrel that can deliver sufficient power, accuracy, and maneuverability to serve you in various scenarios, go for a 9 to 10-inch barrel. A 9 to 10-inch .300 Blackout barrel keeps a gun portable and short enough to wield easily. It’s also long enough to deliver sufficient bullet velocity to hit targets accurately at 100 yards.

Another reason why 9 to 10 inches is the best overall .300 Blackout barrel length is the minimal muzzle rise and comfortable recoil. The reduced recoil and muzzle rise make taking accurate follow-up shots much easier.

The Best Barrel Lengths for .300 Blackout Suppressed

.300 Blackout ammo can be loud, especially when shooting supersonic rounds. Fortunately, you can reduce gunfire noise to protect your ears or hide your position by adding a suppressor to your barrel. However, since a suppressor adds to the length of your gun, you don’t want to add a suppressor and make your gun long and clumsy.

Based on feedback from shooting experts, the best barrel length for .300 Blackout suppressed is 8 to 10 inches. If your barrel is 8 to 10 inches, attaching a 6-inch suppressor will take the barrel’s length to 14 to 16-inches. At 16 inches, .300 Blackout barrel muzzle velocity is close to its peak, giving you a powerful weapon for making accurate long-range shots.

If you want the longest range with a suppressed .300 Blackout barrel, get a 16-inch barrel and add a suppressor. With a 20-inch suppressed barrel, you can achieve a bullet velocity of over 2,630 feet per second (fps), leading to more impactful shots and reduced bullet drop. However, a 20+ inches barrel may be too unwieldy and impractical for anything but target shooting.

The Best Barrel Lengths for .300 Blackout Subsonic

Sound travels at 1,100 fps at sea level on a standard day. When an object travels faster than the speed of sound and breaks the sound barrier, it generates a sonic boom. Supersonic bullets travel fast enough to generate sonic booms, and the resulting noise gives even suppressed gunshots a loud "crack."

Subsonic .300 Blackout rounds fix this problem by traveling slower than the speed of sound. These loads are heavier than most rounds and feature an adjusted powder charge that delivers peak bullet velocity by combusting completely within short barrels.

On the downside, the weight of these bullets prevents them from traveling far and maintaining a flat trajectory. For example, the Hornady Sub-X 190-grain load shot from a 10-inch barrel flies at 1,050 fps and drops 47.6 inches at 200 yards. Based on these figures, if you plan on shooting targets within 100 yards, you can make do with a 10 to 12-inch barrel.

However, if you want to hit targets at over 100 yards, the best barrel length for .300 Blackout subsonic is 16 inches. A 16-inch barrel will provide more velocity to compensate for the weight of the bullet, allowing it to travel further on a flat trajectory. For example, if you shoot the same Hornady Sub-X 190-grain load from a 16-inch barrel, it will drop 33 inches at 200 yards – a 14-inch improvement over shooting with a 10-inch barrel.

The Best Barrel Lengths for .300 Blackout Home Defense

Armed forces in the U.K., U.S., and other countries use .300 Blackout because its stopping power and suitability for close combat are undeniable. If the .300 BLK is good enough for the U.K. and U.S. military, it’s more than enough for home defense.

Besides being powerful and efficient, .300 Blackout rounds are ideal for home defense because they are lethal when fired from short-barreled guns. Short-barreled rifles come highly recommended for home defense because the compactness makes the weapon easy to wield within the walled and close quarters of a home.

.300 BLK ammo fired from a short barrel can hit targets at 100 yards, which is more than enough range for home defense. However, if you want the best barrel length for .300 Blackout home defense, we recommend not going shorter than 6 to 8 inches.

The Best Barrel Lengths for .300 Blackout Pistol

While you can have a 9-inch .300 BLK barrel pistol, the best barrel length for .300 Blackout pistol is 6 inches. A 6-inch .300 Blackout barrel is short enough to carry as a concealed weapon, and drawing and aiming the reasonably sized weapon is hassle-free.

Even though it is short, a 6-inch barrel can generate enough velocity to hit close-range targets. If you want your pistol to have more range, velocity, and accuracy, you can opt for an 8 to 10-inch barrel. However, a longer barrel will lead to a weightier gun, and you may have trouble wielding it with one hand.

The Best .300 Blackout Barrel Lengths for Hunting

A successful hunt requires sneaking up on a target until you're close enough to take a clean and fatal shot. If you get too close to your prey, you may spook it, causing it to run off before you can shoot. With these details in mind, the best .300 Blackout barrel length for hunting is one that can hit long-range targets. The barrel should also deliver enough bullet velocity to hit far-off prey with deadly impact.

As we’ve established, longer barrels deliver the most accuracy and velocity, and the longest .300 Blackout barrel you can get is 16 inches. A 16-inch barrel ensures complete gunpowder burning to fire rounds with maximum force. The barrel's length also allows the bullet to stabilize before exiting the muzzle, leading to a flatter trajectory and better accuracy.

Lastly, a 16-inch barrel provides a long line of sight to improve your aim. All these benefits work together to make a 16-inch .300 BLK barrel the best choice for hunting and other forms of long-range shooting.

.300 Blackout Barrel Length FAQs

Here are answers to common questions asked about .300 Blackout barrel length:

Does .300 Blackout Barrel Length Affect Accuracy?

The length of a .300 Blackout barrel affects accuracy in several ways. For instance, longer barrels generate more bullet velocity. A higher velocity will help a bullet fly with more power and speed, increasing how far a bullet can travel before gravity pulls it off its trajectory.

A long barrel also provides the runway a bullet needs to stabilize fully before exiting the muzzle. The stability provided by the long barrel will help the bullet fly on a flat trajectory and increase its likelihood of hitting its target.

Lastly, barrel length affects a bullet’s twist rate – how much a bullet spins within the barrel when fired. Long .300 Blackout barrels have a tighter twist rate, which helps maintain a high velocity and accuracy when shooting a heavy bullet.

Is .300 Blackout Effective in a 16-Inch Barrel?

In a 16-inch barrel, .300 Blackout ammunition gets impressive velocity and accuracy, allowing you to hit targets over 150 yards away.

What's the Shortest Barrel for .300 Blackout?

The shortest .300 Blackout barrel we have in stock is the 6-inch barrel. We do not recommend choosing a shorter option because the barrel will not be long enough to sufficiently burn gunpowder and provide maximum force to propel the bullet from the muzzle.

How Far Will .300 Blackout Shoot Accurately?

The accuracy of a .300 Blackout barrel will depend on the exact round and barrel length you use. A 125 grain .300 BLK bullet fired from a 16-inch barrel has an effective range of about 500 yards, while the same ammo shot from a 9-inch barrel has an effective range of about 480 yards. 125 and 225-grain .300 ammo fired from both barrel lengths can travel 100 yards without dropping.

Need a .300 Blackout Barrel?

Now that you know the best barrel length for .300 Blackout ammo, you only need to find where to buy a barrel that fits your needs. Fortunately, you don’t have to look far. At Ballistic Advantage, we offer high-quality barrels for AR-style rifles, and you can find one with the perfect length to meet your handling and accuracy preferences.

Visit us today to browse the .300 Blackout barrel lengths we have in stock and place an order to receive your selection at your doorstep.