What cartridge was used in  a standard issue service pistol for the armed forces of the United Kingdom from 1887 until 1963
.455 Webley: .455 Webley is a British handgun cartridge, most commonly used in the Webley top break revolvers Marks I through VI. Webley Revolver: The Webley Revolver (also known as the Webley Top-Break Revolver or Webley Self-Extracting Revolver ) was, in various marks, a standard issue service pistol for the armed forces of the United Kingdom, and the British Empire and Commonwealth, from 1887 until 1963.
.455 Webley