The Webley and Scott Mark VI was the standard issue handgun for officers in British forces in World War I. Weighing two pounds, the Webley was known for reliability and sturdiness. A six-shot revolver, .455 calibre, the Webley had an impressive heft and no doubt inspired confidence in the men carrying it. It is another question, of course, how much use it was to a mounted man; I know my father put no faith in his ability to hit what he aimed at while on horseback. During the charge of Flowerdew's "C" Squadron at Moreuil Wood in 1918, Flowerdew drew his sword, not his Webley, for the attack.
My father owned a Webley when I was young, although not the one he carried as a troop sergeant. That one was abandoned on the field so he could better crawl, wounded, out of the way of bullets and pounding hooves.