Southern Gun Supply

The .223 Remington and 5.56 NATO (5.56x45mm) are similar cartridges but have some important differences:

1. Chamber Pressure:

• 5.56 NATO: Designed to operate at higher pressures (approximately 58,000 psi).
• .223 Remington: Typically operates at lower pressures (approximately 55,000 psi).

1. Chamber Dimensions:

• 5.56 NATO: The chamber is slightly larger, particularly in the throat (the area just before the rifling starts). This allows for more space to accommodate the higher pressures.
• .223 Remington: The chamber has a shorter throat, which can increase pressure if a 5.56 NATO round is fired in a .223 chamber.

1. Interchangeability:

• Firing .223 in a 5.56 Chamber: Safe and common. The lower pressure of the .223 round is well within the limits of a 5.56 chamber.
• Firing 5.56 in a .223 Chamber: Not recommended. The higher pressure of the 5.56 round could lead to unsafe conditions in the tighter .223 chamber.

1. Accuracy:

• .223 Remington: Often favored for precision shooting because of the tighter chamber specifications, which can lead to better accuracy.
• 5.56 NATO: While still accurate, it is generally less precise than the .223 when using the same bullet type due to the looser chamber tolerances.

1. Military vs. Civilian Use:

• 5.56 NATO: Standard issue for military use.
• .223 Remington: More commonly found in civilian markets, particularly for hunting and sport shooting.

In summary, while the .223 Remington and 5.56 NATO cartridges look similar. Many firearms are able to shoot both, but it is critical to ensure that your firearm is properly chambered and can safely fire both rounds. Fortunately for you, we carry a variety of both rounds on our website which can be shipped to you today!