300 Blackout vs 308: Caliber Comparison

The Short Answer: The 300 Blackout excels in close quarters with shorter barrels and offers excellent suppression with subsonic loads, while the 308 delivers superior power and accuracy at longer ranges with better terminal ballistics.

If you’re trying to decide between 300 Blackout and 308, you’ve likely realized these popular calibers serve different purposes despite their similar bullet diameters. This comparison will help you understand which caliber best fits your shooting needs.

The 300 Blackout (also known as 300 BLK or AAC Blackout) was designed specifically for the AR platform, offering versatility in both subsonic and supersonic loads. It performs exceptionally well from short-barrel firearms while maintaining good energy for close-quarters applications and medium-range shooting.

In contrast, the 308 Winchester (7.62×51mm NATO cartridge) has long been the gold standard for medium to long-range shooting. It delivers significantly higher muzzle velocity and energy, making it ideal for hunting larger game and precision shooting at extended distances.

Origins and Design Purpose

The Birth of Two Calibers

The 308 Winchester emerged in the 1950s as the 7.62×51mm NATO cartridge, designed to replace the larger 30-06 Springfield while maintaining similar power in a shorter package. It quickly became popular with hunters and target shooters for its accuracy and performance at medium to long ranges.

In contrast, the 300 Blackout (300 BLK) is much newer, developed around 2010 by Advanced Armament Corporation. The AAC Blackout was created to offer better performance than 5.56mm from short barrels while functioning reliably in the AR platform. A key goal was combining supersonic and subsonic capabilities in one caliber without changing parts beyond the barrel.

Physical Differences

Despite their performance differences, both calibers use bullets of nearly identical diameter (around .308″). The real difference lies in their cases – 308 Winchester uses a larger case with more powder capacity, generating higher pressures and velocities. The 300 Blackout uses a modified 223 Remington case necked up to accept 30-caliber bullets, allowing it to function in standard AR-15 magazines.

Platform Compatibility

One major advantage of the 300 Blackout is its compatibility with the AR-15 platform. Converting a standard 5.56mm AR-15 to 300 Blackout requires only a barrel change – no bolt, buffer, or magazine changes needed. This makes it attractive for AR-15 owners wanting enhanced capabilities.

The 308 Winchester requires larger receivers and components, typically running on the AR-10 platform or bolt action rifles designed for full-power cartridges. This larger size adds weight but contributes to the caliber’s stability at longer ranges.

Barrel Length Considerations

The 300 Blackout was optimized for shorter barrel lengths, performing well even from a 9-inch barrel. It achieves nearly complete powder burn in just 9-10 inches, making it ideal for compact firearms used in close quarters.

The 308 Winchester benefits from longer barrel lengths of 18-24 inches, allowing its substantial powder charge to fully burn and generate maximum velocity. Using a 308 in a short-barrel rifle results in reduced performance and excessive muzzle blast.

Ballistic Performance Comparison

Velocity and Energy

The 308 Winchester outperforms the 300 Blackout in both muzzle velocity and energy by a significant margin. A typical 150-grain bullet from a 308 achieves around 2,800 fps from a 24-inch barrel, generating over 2,600 ft-lbs of muzzle energy. In comparison, a 125-grain supersonic 300 Blackout load from a 16-inch barrel reaches about 2,200 fps with roughly 1,350 ft-lbs of energy.

This difference becomes even more pronounced with subsonic loads. Subsonic 300 Blackout ammunition, typically using 220-grain bullets, delivers velocities around 1,000 fps (staying below the sound barrier) with approximately 500 ft-lbs of energy. The 308 rarely operates in the subsonic velocity range except in specialized applications.

Trajectory and Effective Range

The higher velocity of the 308 creates a flatter trajectory, allowing for more predictable hits at distance. The effective range of a 308 for hunting-sized targets extends comfortably to 800+ yards in capable hands with proper optics.

The 300 Blackout with supersonic loads has an effective range of about 300-400 yards, with accuracy falling off considerably beyond that point. Subsonic rounds limit this range further to about 200 yards due to their slower speed and arching trajectory.

Bullet Weight Options

Both calibers offer versatility in bullet weights, though they excel with different ranges:

• 300 Blackout: Common weights range from 110-125 grains for supersonic loads and 190-220 grains for subsonic ammunition
• 308 Winchester: Typically uses 150-180 grain bullets for most applications, with specialty options from 125 grains up to 220 grains

Performance with Different Barrel Lengths

The 300 Blackout retains much of its velocity even with a short barrel. Moving from a 16-inch to a 9-inch barrel results in only about a 10-15% drop in velocity. This makes it ideal for SBRs (Short-Barreled Rifles) and pistols.

In contrast, the 308 Winchester loses significant performance in shorter barrels. A 16-inch barrel can cause velocity drops of 200-300 fps compared to a 24-inch barrel, with even greater losses in barrels shorter than 16 inches. The 308 performs best with a longer barrel that allows complete powder combustion.

Suppression and Recoil Management

The 300 Blackout offers versatile suppressor performance depending on your goals. With subsonic loads, it provides extremely quiet operation without the sonic crack of bullets breaking the sound barrier. With supersonic loads, a suppressor still reduces muzzle blast while helping manage recoil for faster follow-up shots.

The 308 benefits differently from suppression. While it remains louder than Subsonic 300 Blackout due to its larger powder charge, many shooters add suppressors to 308 rifles primarily to tame the substantial muzzle blast and reduce felt recoil. This improves shooter comfort during extended sessions and helps maintain accuracy during rapid-fire sequences in tactical or competitive environments.

Practical Applications and Use Cases

Hunting Applications

The 308 Winchester has long been a favorite among hunters for its versatility and power. It’s suitable for whitetail deer, elk, moose, and similar-sized game at ranges out to 300+ yards. The heavier bullets and higher velocities provide reliable expansion and penetration on large animals.

The 300 Blackout serves as a capable hunting round for medium-sized game like whitetail deer and feral hogs but at closer ranges (typically under 200 yards with supersonic loads). Many hunters appreciate its lower recoil, which allows for faster follow-up shots when hunting moving targets like feral hogs. Supersonic loads are recommended for hunting to ensure proper expansion and ethical kills.

Home Defense and Tactical Use

For home defense and close-quarters applications, the 300 Blackout offers significant advantages. When paired with a short barrel and suppressor, a 300 Blackout rifle provides:

1. Compact size for maneuvering in tight spaces
2. Reduced noise with subsonic ammunition
3. Sufficient terminal ballistics for defensive purposes
4. Lower risk of over-penetration with certain bullet designs

The 308 Winchester, while powerful, is generally less suitable for home defense due to excessive muzzle blast, recoil, and overpenetration concerns. However, it remains popular in tactical applications requiring engagement at longer distances or penetration of barriers.

Long-Range Shooting

For long-range shooting enthusiasts, the 308 Winchester is clearly superior. It’s a staple in precision bolt gun competitions out to 1,000 yards and serves as an excellent learning platform for long-range shooting skills. The 308’s:

1. Flatter trajectory
2. Better wind resistance
3. Greater energy at distance
4. Wider selection of match-grade ammunition

All contribute to its dominance in this domain. The 300 Blackout simply cannot compete at extended ranges due to its lower velocity and resulting steeper trajectory.

Military and Law Enforcement Use

Both calibers have found roles in specialized military and law enforcement applications. The 308 serves in designated marksman and sniper roles where range and penetration are priorities. The 300 Blackout has gained popularity with special operations units needing suppressed fire from compact weapons, particularly in close-quarters battle scenarios where stealth may be required.

Making Your Choice: Reloading for Performance

When it comes to choosing between 300 Blackout vs 308, there’s no “correct” answer. The better choice depends entirely on your specific needs and shooting preferences. The 300 Blackout excels in close quarters with shorter barrels and suppressed applications, while the 308 dominates at longer ranges with superior ballistics and energy.

For many enthusiasts, the real fun begins when handloading these calibers. Reloading allows you to fine-tune your loads for optimal performance in your specific firearms, whether you’re looking for subsonic 300 Blackout loads for whisper-quiet operation or precision 308 loads for long-range shooting.

Why Choose Berry’s Bullets?

Our superior-plated bullets deliver outstanding performance for reloaders working with both calibers. Starting with a swaged lead core and finished with precise electroplated copper, our bullets offer several advantages:

• Unparalleled accuracy from our precision manufacturing process
• Consistent bullet weight for predictable ballistic performance
• Reliable feeding in semi-automatic platforms
• Corrosion-resistant copper coating that maintains integrity in various conditions
• Multiple bullet design options including round nose, flat nose, and hybrid hollow point

Berry’s extensive selection of bullet weights and styles gives reloaders the flexibility to create loads tailored to their specific needs, whether you’re loading for a short-barrel 300 Blackout or a precision 308 bolt gun.

For reloaders seeking the finest components, look no further than Berry’s Bullets to elevate your shooting experience.