223 wylde, so yes, you can shoot 556 and 223, but you would "maximize" efficiencies by using 223
The good thing about .223 Wylde and a main reason it was created — is to fire both 5.56 NATO and .223 Remington. The “.223 Wylde” name itself is not an actual cartridge but rather a specific design to the chamber of the barrel. Also, “Wylde” is the last name of the designer — Bill Wylde.