In 1868, the British—who subscribed to the theory that a slow-moving and heavy bullet provided good stopping power—brought out their first double-action handgun chambered for the .450 Adams. The Adams served until 1880 when the revolver and round were replaced by the .455 Mark I cartridge and the Webley revolver. (The Adams round, which is a blackpowder item, was a short version of the Webley rounds.)
The Webley handgun is a large double action that breaks open for reloading. The extractor ejects all of the rounds at the same time—a feature desirable in a combat handgun. To get into all the Webleys and their various rounds would take up a lot more space than this column has because there are so many variations. Probably the most common round was the .455 Webley. It is a rimmed cartridge slightly shorter than a .45 ACP round.
The Mark VI shown in the photos is in good shape but unfortunately was modified to shoot .45 ACP ammo with a moon clip. The moon clips work okay and will speed up the reloading, but it is difficult to put rounds in them without a tool made for that job. Both the clips and tools are still available at various distributers. This Webley conversion was a common one since the .45 ACP is easier to get than any of the Webley rounds, although, of course, the modification means the gun is no longer original.
If you do have an original Webley .455, ammo for it is not impossible to find. Hornady made brass for it until recently, although the supply has dried up. However, Fiocchi makes ammo for it, and it’s available on that company’s website.
The bullet diameter is usually listed as .455, but cast .452 bullets will shoot okay—especially those with hollow bases. They are normally heavier than standard, usually around 262 grains. The .45 Colt or .45 Auto Rim can be modified to be used in the Webley guns. The rim has to be thinned and the case shortened, but they’ll work once these operations are completed.