Witness reports and actual victims support a more likely scenario of a full-auto 9mm sub-machinegun. Multiple magazine reloads. A surviving victim took 12 rounds. Believable with 9mm, but not with 5.56 NATO ammo.
Hey, to that vacuum skull Grayson, all mean looking guns are the same. Maybe he got it confused with the SAW? (They’re both 5.56 at least.)
Squad Automatic Weapon (SAW), M249
Cyclic: 725 rounds per minute
Sustained: 85 rounds per minute
http://fas.org/man/dod-101/sys/land/m249.htm