User blog comment:Argorrath/Treyarch posts a message of zombies; possibly hinting to a DLC 4/@comment-60.225.61.85-20130803064624/@comment-25494464-20130803224556

The B.A.R.'s official designation was 'M1918', so that wouldn't be there either. The M1911, Springfield, Kar98k, Gewher 98, Maxim Gun (Maxim, not Maxis), etc. are all possible guns that can appear if this map truly is set in 1917.