.223 Remington is a small, high-velocity centerfire rifle cartridge widely used in AR-15-pattern and bolt rifles. It is closely related to, but not identical to, the 5.56 NATO.

.223 Remington is a lightweight, flat-shooting cartridge popular for target shooting, training, and varmint and predator hunting, with mild recoil that makes it easy to shoot accurately. Ammunition is among the most available and affordable centerfire rifle ammo. The relationship to 5.56 NATO matters: .223 is loaded to lower pressure, and while 5.56 chambers generally handle .223, a .223-marked chamber should not be fed 5.56 — so the chamber marking on a specific rifle is worth verifying. It suits target shooters, varmint hunters, and general AR-15 use.

General information about this caliber — not a recommendation for this specific firearm.