A well composed 38 page dissertation written by David Thomas - focussed mostly on the Webley revolvers in their various 'Marks' and it is complete with photographs and copious references - as you'd expect.
Page 25 tells how as the war progressed many officers bought and carried pocket semi-autos to supplement their large holster packed .455" revolvers;
"The Sporting Goods Review notes: It is quiet usual now for an officer to arm himself not only with the Webley .455 service revolver but also with an automatic pistol of about .32 calibre. the latter weapon, owing to its compactness and comparative lightness, is found to be very handy for carrying in the pocket during night patrolling. With a couple of spare magazines the officer can provide himself with practically all the ammunition he is likely to need during his spell of duty."
- A worthwhile read that illuminates the ongoing need for everyone using a handgun to be properly trained and practiced.
One section tells of 22 VCs won for promptness and marksmanship in the use of the pistol - including on 5th June 1915:
"Lieutenant Moor VC of the Hampshire Regiment . At Krithia in Gallipoli he stopped a precipitate retreat of elements of 29th Division with his revolver by shooting the leading four soldiers."
Australian George Raymond Dallas Moor VC
(Died in France November 1918)
I looked this up by Googling it and found all the background history. Certainly this event would be very controversial today. - A Victoria Cross awarded to an eighteen year old officer for shooting "deserters" running to save their lives. That Gallipoli invasion was one terrible mess with our Colonial soldiers being controlled and disciplined by 'old school' British trained officers from the 'Ruling Classes'.
Second Lieutenant Moor received his Regular Commission barely two month later on 1 August 1915.