User blog comment:JoeRamirez/Call of Duty Modern Warfare 3 Weapons Wishlist./@comment-92.6.149.17-20110402011823/@comment-74.207.186.69-20110403024626

No, the M4A1 is not a shortened version of the M-16A4 because the M4 was designed in 1992 and the M-16A4 wasnt designed until 2005, though they are from Colts AR-15 weapons family.