5.56 NATO vs .223 Remington: Which is Better and Why
When comparing 5.56 NATO vs .223 Remington, many shooters are confused because the cartridges look identical, but they aren’t fully interchangeable. Both are popular for AR-15 rifles, hunting small to medium game, and tactical shooting, yet their pressure ratings and case dimensions differ significantly.
Understanding the Difference Between 5.56 NATO and .223 Remington
The 5.56 NATO is loaded to a higher pressure than the civilian .223 Remington, giving it a flatter trajectory and improved penetration over longer distances. While the .223 Rem may have slightly higher muzzle velocity, it loses speed faster downrange.
Key Differences:
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Pressure: 5.56 NATO ~58,000 psi, .223 Rem ~55,000 psi
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Case Length: 5.56 NATO ~.125 inches longer
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Chamber Compatibility: Firing 5.56 in a .223 barrel can be unsafe
These differences mean that not all rifles can safely shoot both cartridges. Shooting a .223 in a 5.56 chamber is generally safe, but performance can be reduced.
Ballistics Comparison: 5.56 vs .223
| Distance | 5.56 NATO | .223 Remington |
|---|---|---|
| Muzzle | 3,130 ft/s | 3,250 ft/s |
| 100 yd | 2,740 ft/s | 2,849 ft/s |
| 500 yd | 1,484 ft/s | 1,557 ft/s |
| Distance | 5.56 NATO | .223 Remington |
|---|---|---|
| Muzzle | 1,196 ft-lbs | 1,290 ft-lbs |
| 100 yd | 917 ft-lbs | 991 ft-lbs |
| 500 yd | 269 ft-lbs | 296 ft-lbs |
While the .223 has slightly higher velocity and energy at short ranges, the 5.56 is optimized for penetration and lethality at longer distances due to higher chamber pressure.
Uses for 5.56 NATO and .223 Remington
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Hunting: Both cartridges are effective for varmint hunting, coyotes, and whitetail deer at ranges under 100 yards.
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Target Shooting & Competitions: Popular for AR-platforms in tactical and precision shooting.
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Military & Tactical Use: 5.56 NATO remains a standard military cartridge, optimized for M16 and M4 rifles.
History of the .223 Remington
The .223 Remington debuted in 1960, designed for civilian AR-15 rifles and varmint hunting. It evolved from the .222 Remington Special, which was primarily a bench competition round. Over time, it became the parent cartridge for the militarized 5.56 NATO.
History of 5.56 NATO
Developed in the 1970s, the 5.56x45mm NATO was designed for military use with higher pressures for improved penetration and lethality. Officially adopted by NATO in 1980, it replaced the heavier 7.62x51mm cartridge. The 5.56 allowed soldiers to carry more ammunition while maintaining effective performance.
Major Differences Between 5.56 and .223
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Pressure Loading: 5.56 NATO is ~3,000 psi higher than .223
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Case Length & Throat: 5.56 has a longer case and chamber throat (~.125 inches)
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Rifle Compatibility: Only rifles chambered for 5.56 can safely handle its higher pressure
Why 5.56 NATO is Often Better Than .223 Remington
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Flatter trajectory at longer distances
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Better penetration in tough targets
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Optimized for 20-inch barrels commonly found on military and civilian AR-15s
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More versatile for hunting, tactical use, and target practice
While the .223 is great for hunting small game and shooting competitions, the 5.56 provides a safer margin and improved performance in rifles chambered for both rounds.
Criticism of the 5.56 NATO
The 5.56 can perform differently in shorter-barreled rifles like the M4 Carbine, where lower muzzle velocity reduces stopping power. Barrel length and twist rate significantly impact performance, which has led to some debate on its lethality.
Closing Thoughts
Both 5.56 NATO and .223 Remington are excellent cartridges with similar dimensions, but the higher pressure, longer case, and optimized design of 5.56 make it the superior choice for most applications. For hunting, tactical shooting, or AR-15 enthusiasts, selecting the right cartridge ensures both safety and performance.