223 Vs 5.56 Ammo Comparison.

Understanding The Difference Between The Two Popular Cartridges.

5.56 NATO and .223 Remington, both are powerful ammo calibers. The battle between 223 vs 556 is a heated one, with many gun enthusiasts arguing over the superiority of each. The difference in bullet diameter may be small, but the impact on bullet specifications, weight, stopping power, magazine capacity, and muzzle velocity is significant.

223 Vs 5.56 Ammo

As a content editor at Bulk Cheap Ammo, I've previously compared the two most popular handgun calibers: 300 Blackout vs. 556. Let's continue this journey by comparing the 556 ammo with another popular caliber, 223 ammo.

The following sections will analyze the differences between 223 and 556. This comparison will help you choose the best rifle caliber to suit your needs.

223 vs 556: Brief overview

The .223 and .556 cartridges are among the most popular rifle ammunition worldwide. The .223 and .556 cartridges are both popular rifle cartridges, often used in semi-automatic rifles and some bolt-action rifles. The .223 cartridge is a civilian version of the military 5.56x45mm cartridge, while the 5.56x45mm is the standard round of NATO militaries.

223 vs 556: Brief overview

They are commonly used for hunting, sport shooting, and military applications. This comparison will explore the differences and similarities between the two cartridges and provide recommendations based on their intended use.

223 vs 556: History and Development

The .223 and .556 cartridges were both developed in the mid-20th century. The .223 cartridge was designed for civilian use and was later adopted by the military, while the .556 cartridge was designed specifically for military use. Both cartridges have undergone numerous modifications over the years to improve their performance.

223 vs 556: Cartridge Specifications

The .223 and 5.56 cartridges have different dimensions and physical characteristics, resulting in different ballistics and performance. The .223 cartridge is typically lighter and has a smaller diameter than the .556 cartridge, which results in lower recoil and shorter effective range.

Browse 5.56Ammo | Browse 223 ammo

  223 Ammo 5.56 Ammo
Parent Case .223 Remington 223 Remington
Bullet Diameter 0.224 in 0.224 in
Neck Diameter 0.253 in 0.253 in
Base Diameter 0.376 in 0.377 in
Case Length 1.760 in 1.760 in
Overall Length 2.26 in 2.260 in
Case Capacity 31.4 grains 28.5 grains
Max Pressure (SAAMI) 55000 psi 55114 psi

223 vs 556: Ballistics and Performance Differences

It is important to note that while a rifle chambered for .223 can safely fire 5.56x45mm ammunition, the reverse is not true. Firing a 5.56x45mm cartridge in a rifle chambered for .223 can result in dangerous overpressure and potential damage to the firearm. It is always important to use the appropriate ammunition for your firearm.

The .223 and .556 cartridges are commonly used in AR-15 rifles, but they have some differences in performance and ballistics. Here are some key differences.

Chamber Pressure: Going by SAAMI standards, the .556 cartridge has a higher chamber pressure than the .223 cartridge. The maximum average pressure for a .223 cartridge is around 55,000 PSI, while for the .556 cartridge, it is around 62,000 PSI.

Velocity: The .556 cartridge typically has a higher velocity than the .223 cartridge. This is because of the higher chamber pressure, which allows for more efficient gunpowder burning. The average velocity of a .223 cartridge is around 3,200 feet per second, while for the .556 cartridge, it is around 3,300 feet per second.

Bullet Weight: The .223 cartridge typically has a lighter bullet compared to the .556 cartridge. The most common bullet weight for a .223 cartridge is 55 grains, while for the .556 cartridge, it is 62 grains.

Accuracy: The .223 cartridge is generally more accurate at longer ranges compared to the .556 cartridge. This is because the lighter bullet is less affected by wind drift and bullet drop. However, the .556 cartridge is better suited for medium-range engagements, where its higher velocity and the heavier bullet can provide better terminal ballistics.

223 vs 556: Recoil

The lower recoil of the .223 cartridge makes it more comfortable to shoot and more accessible to control than the .556 cartridge. However, the .556 cartridge has a longer effective range and is generally more accurate due to its higher muzzle velocity.

223 vs 556: Terminal Performance

The effectiveness of the .223 and .556 cartridges varies depending on the scenario and the type of bullet used. Both cartridges are capable of delivering lethal force, but the .556 cartridge is generally more effective against armored targets due to its higher velocity and energy.

223 vs 556: Availability and Cost

Both .223 and 5.56 ammo are widely available, but the cost of the two cartridges varies depending on the brand, bullet weight, and quantity purchased.

Generally, .223 Remington ammunition is more widely available and less expensive than 5.56x45mm NATO ammunition.

223 vs 556: Legal Considerations

There are differences in legal regulations and restrictions that apply to the use of .223 and .556 ammunition, particularly with hunting and sport shooting. It is essential to familiarize oneself with these regulations before using either cartridge.


In conclusion, the .223 and .556 cartridges have different characteristics and performance capabilities, making them more suited to different applications. It is recommended that individuals choose the cartridge that best suits their intended use case based on factors such as recoil, accuracy, terminal performance, availability, and legal considerations.

FAQ’s About 223 vs 556

Q. 223 vs 556: Are They the Same?
Ans: Both cartridges have a similar appearance and are loaded with similar bullets. The main difference between the two is the pressure they generate when fired.

Q. Can You Load 223 Rounds in a 5.56 Magazine?
Ans: Yes, you can load 223 rounds in a 5.56 magazine. Just be sure to note that the ammo loaded in the 5.56 Magazine is 223 Rem ammo.

Q. Can I shoot 223 Remington in my 5.56 NATO Rifle?
Ans: Yes, you can safely shoot .223 Remington ammunition in a rifle chambered for 5.56x45mm NATO.

Q. Which cartridge is better for hunting or self-defense?
Ans: Both cartridges can be used for hunting or self-defense, but their choice may depend on personal preferences and the specific application.

Lisa Earnest

Lisa Earnest

Feb, 21, 2023

Lisa Earnest has been a part of the Bulk Cheap Ammo team since 2018 and serves as the editor of Bulk Cheap Ammo content.

With a flair for language and an unwavering dedication to shooting sports, Lisa's diverse expertise combines to create an unforgettable experience for our audience.

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