.223 vs .300 Blackout: A Comparison
Hey all, we here at True Shot Academy are going to talk about two popular AR-15 platform cartridges today. The .223 Remington (also called .223 Rem or simply .223) and .300 Blackout (also called .300 BLK or 300 AAC Blackout) represent different approaches to achieving optimal performance from the AR-15 platform, with each offering distinct advantages for specific applications. Today we will compare these influential cartridges across ballistic performance, practical applications, and real-world considerations. Without further ado, let's examine these two AR-15 chamberings.
Historical Development: Military Standard vs. Specialized Design
The .223 Remington emerged from development work in the late 1950s as a commercial version of what would become the 5.56mm NATO cartridge. Formally introduced in 1962 by Remington Arms, the cartridge was quickly adopted by the U.S. military in 1963 as the 5.56 alongside the M16 rifle. The design prioritized high velocity with a lightweight bullet, creating a flat-shooting cartridge with minimal recoil suitable for military applications.
The .300 Blackout represents a much more recent development, created by Advanced Armament Corporation (AAC) in collaboration with Remington Defense. Introduced in 2010 and SAAMI-standardized in 2011, the cartridge was designed specifically to address perceived limitations of the 5.56mm. The primary design goals included creating a .30 caliber cartridge that would function reliably in AR-15 platforms, provide superior suppressed performance, and deliver enhanced terminal ballistics compared to 5.56mm NATO.
These different origins explain the cartridges' divergent performance profiles. The .223 emerged from military requirements emphasizing lightweight ammunition, flat trajectory for longer-range engagements, and compatibility with compact service rifles. The .300 Blackout came from a focused effort to maximize terminal ballistics and suppressed performance within existing AR-15 dimensional constraints, particularly for close-quarters battle (CQB) and special operations applications.
Cartridge Specifications and Physical Characteristics
These cartridges share the critical requirement to function in the AR-15 platform but differ substantially in their dimensions and design approach. The .223 features a rimless, bottleneck case measuring 1.76 inches in length with a case mouth diameter of .224 inches. It fires .224" diameter bullets typically weighing between 35 and 90 grains, with 55, 62, and 77 grains being the most common loadings. The cartridge operates at a SAAMI maximum pressure of 55,000 psi.
The .300 Blackout utilizes a rimless, bottleneck case of identical length (1.368 inches) but with a substantially larger case mouth diameter of .308 inches. It fires .308" diameter bullets ranging from 78 to 240 grains, with 110-125 grains common for supersonic loads and 190-220 grains typical for subsonic applications. The cartridge operates at a SAAMI maximum pressure of 55,000 psi but achieves various velocity profiles depending on bullet weight.
The critical design achievement of the .300 Blackout lies in its compatibility with existing AR-15 components. The cartridge was specifically engineered to function in standard AR-15 magazines at their full capacity and to require only a barrel change to convert from .223/5.56. This compatibility dramatically reduced adoption barriers compared to other alternative cartridges that require different bolts, magazines, or other components.
Purchase .223 Ammo
Ballistic Performance Comparison
The ballistic profiles of these cartridges reveal substantial performance differences despite their common platform.
The .223 typically propels a 55-grain bullet at approximately 3,000-3,200 fps from a 16-inch barrel, generating around 1,282 foot-pounds of energy. Heavier 62-grain bullets achieve approximately 3,000 fps, while match-grade 77-grain projectiles travel at roughly 2,750 fps. The cartridge's high velocity creates a flat trajectory within typical engagement distances (under 400 yards) but suffers from rapid velocity loss with lighter bullets due to their relatively poor aerodynamic efficiency.
The .300 Blackout presents two distinct performance profiles depending on loading. Supersonic loads drive 110-125 grain bullets at 2,200-2,400 fps from the same barrel length, producing approximately 1,300-1,400 foot-pounds of energy—similar to .223 despite the lower velocity. Subsonic loads propel 190-220 grain bullets at approximately 1,000 fps, generating around 500 foot-pounds of energy specifically for suppressed applications.
Terminal performance differences prove significant, particularly with standard loadings. The .300 Blackout's heavier bullets deliver substantially more momentum and energy transfer at close to moderate ranges, with terminal performance approaching that of the 7.62x39 Soviet cartridge. The larger diameter creates wider wound channels, and the enhanced sectional density provides superior penetration compared to similar weight .223 bullets.
For suppressed performance, the .300 Blackout holds a dramatic advantage. Purpose-designed subsonic loads create minimal sound signature when suppressed, operating below the sound barrier while maintaining adequate terminal performance with heavy bullets. The .223 can be loaded subsonically, but such loads typically fail to cycle semi-automatic actions reliably and deliver poor terminal performance due to the smaller bullet diameter and limited weight options.
Available Ammunition Types
Both cartridges offer diverse ammunition options, though with different emphasis reflecting their typical applications:
.223 Remington Varieties:
- Full Metal Jacket (FMJ): General purpose loadings which commonly feature 55 grain projectiles for training, competition, or plinking.
- Open Tip Match (OTM): High-accuracy loads with 69-77 grain Sierra MatchKing and similar bullets.
- Varmint/Predator: Lighter bullets designed for rapid expansion on smaller game.
- Defensive/Tactical: Specialized loads with controlled fragmentation or expansion characteristics.
- Barrier-Blind: Enhanced-performance bullets designed to maintain trajectory through intermediate barriers.
.300 Blackout Varieties:
- Supersonic Tactical: 110-125 grain bullets optimized for terminal performance at supersonic velocities.
- Subsonic Suppressed: 190-220 grain bullets designed specifically for suppressed applications.
- Expanding Subsonic: Specialized subsonic loads with controlled expansion capabilities
- Hunting Loads: Options designed for medium game at moderate ranges.
- Training/Practice: Full metal jacket options in both supersonic and subsonic configurations.
The .223 Remington enjoys substantially greater commercial availability and variety due to its military adoption and widespread use. The .300 Blackout, while growing rapidly in popularity, typically costs more than comparable quality .223 ammunition, reflecting both lower production volumes and the larger, heavier bullets used.
Major Ammunition Manufacturers
Most major ammunition manufacturers now produce both cartridges, though with varying emphasis:
Hornady offers extensive options in both calibers, including their Frontier, Black, Custom, and Match lines for .223 Remington and their Black and Custom lines for .300 Blackout. Their .300 Blackout offerings specifically emphasize both supersonic and subsonic performance.
Federal produces both calibers across multiple product lines, with their American Eagle, Premium, and Fusion offerings available in both chamberings. Their specialized Tactical line for .300 Blackout includes purpose-built subsonic loads optimized for suppressed performance.
Remington, as the original developer of both cartridges (in partnership with AAC for the Blackout), manufactures extensive options including UMC, Premier Match, and Core-Lokt lines for various applications.
Specialized manufacturers like Nosler, Barnes, and Underwood produce match-grade and hunting-specific loads in both cartridges, with particular emphasis on maximizing the .300 Blackout's terminal performance potential with their monolithic copper bullets.
Companies like Sig Sauer and Ammo Inc. focus specifically on maximizing the .300 Blackout's suppressed performance capabilities, developing loads that reliably cycle AR-15 actions while remaining subsonic across varying environmental conditions.
Purchase .300 Blackout Ammo
Firearms Chambered in Each Caliber
The AR-15 platform dominates applications for both cartridges, though with different emphasis:
.223 Firearms:
Virtually every major AR-15 manufacturer offers multiple .223 Remington/5.56 NATO models spanning from pistol configurations through carbines to dedicated precision variants. Companies like Colt, Daniel Defense, BCM, Smith & Wesson, Ruger, and dozens of others produce everything from mil-spec carbines to specialized competition and precision rifles.
Beyond AR-15 platforms, the cartridge appears in numerous other designs including bolt-action rifles from nearly every major manufacturer, various semi-automatic sporting rifles, and even some lever-action offerings. This diversity reflects the cartridge's status as perhaps America's most popular centerfire rifle chambering.
.300 Blackout Firearms:
Most major AR-15 manufacturers now offer .300 Blackout options, with companies like Daniel Defense, BCM, CMMG, and Sig Sauer producing dedicated models optimized for the cartridge. These typically emphasize shorter barrel lengths (8-12 inches) that maximize the cartridge's effectiveness in compact platforms, often paired with suppressors.
The cartridge has also appeared in bolt-action rifles from manufacturers like Ruger, Savage, and Howa, though these represent more specialized offerings compared to their .223 counterparts. Several hunting-oriented AR platforms emphasize the .300 Blackout's enhanced terminal ballistics for medium game at woodland ranges.
Converting existing .223 Remington AR-15s to .300 Blackout requires only a barrel change, maintaining compatibility with the original bolt, magazine, and other components. This simple conversion path has significantly contributed to the cartridge's growing popularity.
Practical Applications and Use Cases
These cartridges excel in different practical applications based on their performance characteristics:
The .223 Remington performs best for:
- General-purpose AR-15 use where ammunition cost and availability matter.
- Varmint and predator hunting where high velocity with lighter bullets is advantageous.
- Applications requiring flatter trajectory and extended effective range.
- Competitive shooting where minimal recoil enhances rapid target transitions.
- Situations benefiting from the widest possible ammunition selection and availability.
The .300 Blackout excels at:
- Suppressed applications where minimal sound signature is crucial.
- Short-barreled rifle (SBR) or AR pistol configurations where full powder burn is achieved in shorter barrels.
- Medium game hunting at moderate ranges where enhanced terminal performance is beneficial.
- Home defense scenarios where overpenetration concerns favor heavier, slower bullets.
- Applications requiring both supersonic and subsonic capability from the same firearm.
The choice between these cartridges typically hinges on specific intended use cases and shooting environments. For general-purpose use, longer-range shooting, and applications where ammunition cost matters, the .223 Remington provides practical advantages. For suppressed shooting, compact weapons platforms, and enhanced terminal performance, the .300 Blackout offers meaningful benefits despite higher ammunition cost.
Conclusion
The .223 Remington and .300 Blackout represent different optimization priorities for the AR-15 platform. The .223 Remington prioritizes high velocity, flat trajectory, minimal recoil, and compatibility with global military standards. The .300 Blackout emphasizes terminal performance, suppressed capability, and optimal function from shorter barrels while maintaining compatibility with standard AR-15 components.
The increasing popularity of the .300 Blackout demonstrates its successful execution of design goals, particularly for suppressed shooting and applications requiring enhanced terminal ballistics from compact platforms. Meanwhile, the .223 Remington maintains its dominant position for general-purpose, competition, and longer-range applications due to its flatter trajectory, lower cost, and universal availability.
All in all, both cartridges serve their intended purposes effectively, with the optimal choice depending on the shooter's specific priorities and applications. We here at True Shot Ammo carry an extensive selection of both .223 Remington ammo and .300 Blackout ammunition in addition to our inventory of ammo for sale. Our range of ammunition for sale includes popular calibers and gauges like 9mm, 5.56, 12 gauge, .22 LR. Whether you want to buy .223 ammo, buy .300 Blackout ammo, or buy bulk ammo, we have got you covered. As always, happy shooting.
