The Sport 2 will chamber and fire either round, as per S&W. .223 / 5.56 cases are basically the same in that reloading dies will reload either. The difference comes in slightly higher pressure in 5.56 ammo, and the bullet length / free bore interface between rifles chambered for either as compared to those chambered for just .223. If you reload, .223 brass is actually nicer, as you don't have a primer crimp to remove. Your rifle will work fine with .223 ammo.

Larry