The .455 Webley Ammo is a British cartridge created for handguns and has been mostly used in the Webley top break Marks. The .455 Webley Ammo features a rimmed cartridge using a .45 caliber Ammo. It fires at a low velocity of 650 feet per second. This resulted in the bullet delivering a mild recoil to the user. The British and Commonwealth forces used the .455 Webley Ammo until the end of World War II. There have been many variants in the use of the .455 Webley Ammo. Mk I was the starting point for this bullet and was shortened to compensate for better combustion; this created the Mk II of the .455 Webley Ammo. Mk III used a 218-grain bullet variant but proved to be unsuitable for use by the military of the UK. Mk IV also proved unsuccessful, and in the end, the Mk II was reintroduced. Finally, the Mk VI proved adequate and was chosen to be used for World War II due to superior performance.
The .455 Webley Ammo was designed and manufactured by Royal Laboratory Woolwich Arsenal in 1891, and it was redesigned five times to achieve perfection.
The .455 Webley Ammo has a long history of serving the needs of the military. It was used in the Second World War by the United Kingdom Military.