This man enlisted as William James Clarke, and so is "mis-filed" in WO 363 (WW1 Service Records):

David GRAY joined (as CLARKE) the Royal Artillery December 1889, declaring age 23y, born Co Antrim (Glenavy? Glenarm?). Signed declaration of true name (GRAY) in 1890 while serving in Malta. Regt No: 75932.

Promoted to Bombardier October 1891.
Committed suicide at Fort Wallington, Fareham, April 1892.

Anc****y, CLA, pages 184278-184288