.223 / 5.56

The .223 Remington and 5.56 NATO calibers are the popular centerfire cartridge in America. Stock up with the best ammo today!  As a side note, we go through differences in the Bullet Calibers & Types lessons, but basically you can shoot .223 ammo in a 5.56 barrel, but since 5.56 may have higher pressures, you should not shoot them in a .223 Rem barrel. Please do not confuse .223 Remington with 223 Wylde, in which you can shoot both, 5.56 and .223!