HMS M.27 shared engine design with M.26. Her main gun was also transfered to the Western Front. She received a BL 6" Mk.II from HMS Redoubtable, which was later replaced by a Mk.VII. This shows the later mount.
In 1919. Her 6” gun was exchanged with a BL 4" Mk.IX Triple mount - the same type used in the Battlecruiser HMS Renown - before she sailed for Murmansk, in support of White Russian forces.