I just watched the video that John linked. The guy in the video stated that the AUG was NOT 5.56mm chambered, but 223 chambered. That was why he was using Wolf 62 gr 223 test ammunition.
But I went to the Styer USA website and it lists the AUG A3 as being 5.56mm chambered. Can any AUG owners verify that the gun is in fact chambered in 5.56?