I heard, without a doubt, what sounded like a full auto AK-47 or other 7.62 600 RPM weapon in use. No one knows for sure what it was, but it sure sounded like an AK-47 to me. Other's have suggested it was a belt fed 240. It's more likely, in my opinion, for it to have been an AK though. The full auto I heard was not JUST a bump fired AR.