Surname appears as Mackay in Nominal Rolls, as McKay in Archives New Zealand

Embarked Wellington, 9 October 1915; disembarked Suez, 15 November 1915.
Attached to School of Instruction, Zeitoun, 5 February 1916.
Admitted to NZ General Hospital, Cairo, 23 February 1916 (dyspepsia); transferred to Aotea Convalescent Home, Heliopolis, 3 March 1916; rejoined unit, Zeitoun, 24 March 1916.
Appointed Acting Bombardier, 1 April 1916.
Embarked Alexandria to join the British Expeditionary Force, France, 8 April 1916.
Admitted to No 6 Stationary Hospital, Havre, 23 April 1916; transferred to No 4 Convalescent De[pot, 5 May 1916; discharged to Base Depot, Havre, 12 May 1916; to Base Depot, Etaples, 14 May 1916.
Admitted to 24th General Hospital, Etaples, 17 June 1916 (corneal ulcer); transferred to England, 23 June 1916, and admitted to Strood VAD Hospital, 24 June 1916; transferred to No 2 NZ General Hospital, Walton-on-Thames, 5 July 1916; to NZ Convalescent Hospital, Hornchurch, 7 July 1916; discharged to NZ Command Depot, Codford, 15 August 1916; marched in to NZ Field Artillery Reserve Depot, Aldershot, 18 January 1917.
Proceeded overseas to France, 10 February 1917; rejoined Divisional Ammunition Column, in the field, 14 March 1917.
Detached to Army Rest Camp, 2 July 1917; rejoined unit, 17 July 1917.
On leave to United Kingdom, 31 January 1918; rejoined unit from leave, 18 February 1918.
Admitted to No 3 NZ field Ambulance, 1 May 1918 (infected spermal cord); discharged to unit, 6 May 1918.
Detached on duty to United Kingdom, 16 July 1918.
Commenced return to New Zealand from Plymouth on board HMNZT 'Ionic', 24 August 1918; discharged (termination of period of engagement), 13 December 1918.
War service: 3 years 101 days (of which 1093 days were abroad) AWMM