The .223 Remington cartridge's recoil, as well as that of almost identical 5.56x45mm NATO cartridge, is negligible compared with the .30-06 and .308/7.62mm NATO cartridges that dominated individual weapons used by American troops from 1903 until 1966. Soldiers persistently criticized the smaller round for its lack of "stopping power." The small-diameter bullet travels at high speed, and frequently passes through enemy soldiers without inflicting immediately visible injury.
The .223 cartridge was introduced to the civilian market in January 1964, and a few weeks later, in February 1964, the US Air Force adopted the cartridge as the 5.56x45mm for the new M-16 rifles. The .223 was the released to the civilian market as a rifle cartridge for use as a varmint and predator hunting cartridge. This mild recoil cartridge proved popular among other shooting communities. The flat shooting and excellent accuracy of the cartridge were admired by hunters who found it effective on medium size predators, such as coyote, out to 300 yards. Some hunters use it on game as large as deer, but several jurisdictions did not allow the .223 for deer hunting, as the bullet diameter or muzzle energy were not sufficient for a humane kill.
The .223 Remington was also popular among competitive shooters, and is found at Service Rifle and F-Class matches, in use for precision shooting at ranges up to 1000 yards. The .223 is also popular among 3-gun shooters where the mild recoil allows for light rifles with high magazine capacity to be used for fast and accurate shooting.
Law enforcement agencies found the .223 to be a valuable firearm. It can be found in patrol cars and used in place of the 12 gauge shotgun when a longer or more precise shot is needed. Some departments have also found it to be useful for urban sniping operations.
The .223 Remington is actually a .224 diameter bullet. The bullet weights commonly range from 36 to 77 grains. The muzzle velocities from a rifle span 2700 to 3700 feet per second, with muzzle energies from 1100-1300 foot pounds. Since the .223 Remington is one of the most popular cartridges in America, firearms manufacturers are regularly expanding and refining their products chambered for the .223.
Some AR-15 type rifles are chambered for the commercial .223 Remington, while others are chambered for the military 5.56x45mm. The two cartridges are not the same. Due to different case dimensions, the 5.56 throat and case are designed so that if they are fired in a rifle chambered for .223, it would result in potentially dangerously high pressures. These pressures could damage the firearm and or injure the shooter. On the other hand, the .223 ammunition can be used in firearms chambered for the 5.56mm without problems.
The 5.56mm NATO cartridge may be identified by its appearance, the painting of projectile tips, the stamping of the manufacturer's initials and year of manufacture on the base of the cartridge case, and the markings on the packing containers. When removed from the original packing container, the cartridge may be identified by its physical characteristics. The M193 and M196 cartridge for the M16 can be fired with the M249, but accuracy is degraded; therefore, it should only be used in emergency situations when M855 or M856 ammunition is not available.
Exaggerated claims were made by Colt prior to the shift from the M14 to the Ar-15/M16. One commercial asserted: "Unsurpassed as a Sniper Rifle both accurate and lethal, at 500 yards the AR-15 makes a complete penetration of 10-gauge steel, or both sides of a steel helmet. On impact the tumbling action of the .223 caliber ammunition increases effectiveness." But bullets do not ‘tumble’. They may yaw and rotate 180 degrees within the body, but the standard definition of “tumble” suggests turning end-over-end through a full 360 degrees. This rarely happens.
Sweden raised complaints about the M16 and its 5.56x45mm M193 projectile during and following the Viet Nam War. But the diplomatic conference that produced the 1980 Convention on Certain Conventional Weapons agreed that wounding characteristics of modern military small arms weapons and ammunition did not provide a basis for a new small arms protocol. More recently, the International Committee of the Red Cross (ICRC) objected to the terminal ballistics of contemporary military small arms ammunition and their alleging inconsistencies with the law of war.
There were complaints that the diminutive 5.56x45mm projectile failed to incapacitate enemy combatants in Iraq and Afghanistan. Through-and-through wounds consistently failed to render the targeted enemy hors de combat, necessitating a soldier shooting his target ten or more times before he ceases to be a threat.
|US Army 5.56mm Cartridges|
|Cartridge, 5.56mm: Ball, M193||5.56x45mm NATO 55-grain FMJ|
|Cartridge, 5.56mm: Grenade, M195||5.56x45mm NATO rifle grenade launching blank cartridge|
|Cartridge, 5.56mm: Tracer, M196||5.56x45mm NATO 54-grain tracer cartridge; red tip|
|Cartridge, 5.56mm: High Pressure Test, M197||5.56x45mm NATO 56-grain high-pressure test cartridge|
|Cartridge, 5.56mm: Dummy, M199||5.56x45mm NATO dummy cartridge|
|Cartridge, 5.56mm: Blank, M200||5.56x45mm NATO blank cartridge|
|Cartridge, 5.56mm: Ball, M202||5.56x45mm NATO 58-grain FMJ cartridge; FN SSX822|
|Cartridge, 5.56mm: Dummy, M232||5.56x45mm NATO dummy cartridge|
|Cartridge, 5.56mm: Ball, XM287||5.56x45mm NATO 68-grain FMJ cartridge; IVI Canada produced|
|Cartridge, 5.56mm: Tracer, XM288||5.56x45mm NATO 68-grain tracer cartridge; IVI Canada produced|
|Cartridge, 5.56mm: Blank, M755||5.56x45mm NATO blank cartridge specially for use with the M234 launcher|
|Cartridge, 5.56mm: Ball, XM777||5.56x45mm NATO FMJ cartridge|
|Cartridge, 5.56mm: Tracer, XM778||5.56x45mm NATO tracer cartridge|
|Cartridge, 5.56mm: Ball, XM779||5.56x45mm NATO FMJ cartridge|
|Cartridge, 5.56mm: Tracer, XM780||5.56x45mm NATO tracer cartridge|
|Cartridge, 5.56mm: Ball, M855||5.56x45mm NATO 62-grain FMJ cartridge; FN SS109; green tip|
|Cartridge, 5.56mm: Tracer, M855||5.56x45mm NATO 63.7-grain tracer cartridge; FN L110; orange tip|
|Cartridge, 5.56mm: Plastic Practice, M862||5.56x45mm NATO plastic projectile training cartridge; blue bullet; Short Range Training Ammunition (SRTA)|
|Cartridge, 5.56mm: Armor Piercing, M995||5.56x45mm NATO plastic projectile training cartridge; blue bullet; Short Range Training Ammunition (SRTA)|
|Cartridge, 5.56mm: Dim Tracer, XM996||5.56x45mm NATO dim tracer cartridge|
|Cartridge, 5.56mm, Practice M1042||5.56x45mm Ultimate Training Munitions training cartridge; specifically for use with the Close Combat Mission Capability Kit|
|Cartridge, 5.56mm, Practice M1071||5.56x45mm Ultimate Training Munitions training cartridge; specifically for use with the Close Combat Mission Capability Kit|
|US Navy 5.56mm Cartridges|
|Cartridge, 5.56mm, Jacketed, Frangible, Mk 255||5.56x45mm NATO 62-grain jacketed frangible cartridge; aka Reduced Ricochet, Limited Penetration (RRLP)|
|Cartridge, 5.56mm, Special Ball, Long Range, Mk 262||5.56x45mm NATO 77-grain OTM/HPBT cartridge|
|Cartridge, 5.56mm, Ball, Carbine, Barrier, Mk 318||5.56x45mm NATO 62-grain OTM/HPBT cartridge|
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