The 7th Dragoon Guards was a Cavalry Regiment that would have had an MG Section as part of its Regimental Headquarters.
The Great War
These weapons would have been brigaded when the Machine Gun Corps was formed in 1915. The guns, and crews, would have been formed into a Machine Gun Squadron.
The Inter-War Period
In 1922, the Machine Gun Corps was disbanded and the guns returned to the Cavalry Regiment as a Machine Gun Platoon.
In April 1922, the 4th Dragoon Guards (two squadrons) was amalgamated with the 7th Dragoon Guards (1 squadron) to form 4th/7th Dragoon Guards.