The .223 Remington is one of the most widely used centerfire cartridges today. Tracing its roots back to the .222 Remington, the .223 was designed to achieve certain ballistics for military use. The .223 Remington, when in its military form, is known as the 5.56x45mm NATO. The differences between the two being the pressures that they are loaded at and the chamber in the firearm itself.
The .223 has established itself as an excellent varmint and target caliber. It dominates all other rifle calibers in competitions such as 3-gun, and has a dedicated following in several other sports due to its low recoil and accuracy potential. Those two attributes coupled with good velocity allow it to excel as a varmint gun also.
When loaded at .223 Remington pressures, our brass is safe to use in any firearm chambered for .223 or 5.56x45mm. If loaded to 5.56 pressures, you need to use firearms labeled for use with 5.56mm. It can be unsafe to fire 5.56mm ammunition in firearms with a .223 Remington chamber.
If out of stock check out our 5.56x45mm case.
**WARNING** In firearms that use a floating firing pin (such as the AR-15 and its variants), dropping the bolt on a chambered round could lead to a slam fire. It is important that these firearms are loaded from the magazine so that the bolt loses inertia when it strips a round from the magazine. It is also important NOT to use sensitive primers that aren’t designed for use in an AR, as this increases the chance of a slam fire.
