1940 was at a time when the Vickers .303-inch Mk VI, VI* and VII and .5-inch Mk V were being replaced by the Besa machine gun in both the medium and heavy role – 7.92mm and 15mm replaced .303-inch and .5-inch respectively.
These battalions were organised from units of the Royal Tank Regiment and tank-equipped cavalry regiments.
A full transcript of the following War Establishments are available as PDF downloads:
- III/1931/33 A/3, 27th March 1940, An Army Tank Battalion, which was equipped with tanks largely armed with the Vickers machines guns.
- III/1931/33 A/4, 21st May 1941, An Army Tank Battalion, showing that the tanks were now much more varied and the armament depended upon the type of tanks used by specific units.
- The National Archives, WO 24/937, War Establishments 1940 January to June.
- The National Archives, WO 24/929, War Establishments 1941 January to June.