User blog comment:JoeRamirez/Call of Duty Modern Warfare 3 Weapons Wishlist./@comment-1866089-20101207211327/@comment-1866089-20101208013042

the M4A1 is an american design featuring a 14.5 inch barrel and full auto capability

the C8 SFW is candian with a 16 inch barrel for greater accuracy and other real world refinements