User blog comment:Awyman13/BF4 Confirmed & Speculated Weapons/@comment-5263920-20130806031049/@comment-4563909-20130806122030

In my opinion, it's either a fictional labeling of a current M14-style rifle (or a fictional future variant altogether)

or...

A typo/placeholder for an M14-style weapon from previous games (Mk. 14, M39, etc).