The 5.56mm NATO round has been the gold standard AR-15 cartridge for well over 60 years. It has been the ammo issued to our frontline soldiers for over a generation and has seen combat on 5 continents in the hands of the U.S. Military and our NATO allies. However, some shooters wanted more out...

Many shooters will assert there is no difference between .223 Remington and 5.56x45mm NATO and that you can safely fire both from the same rifle. Others will contest that assertion, “The two ammo types are different!” But which one is right? Who is correct? Although the external dimensions of...