The Webley Revolver was, in various marks

Mark (designation)

The word Mark, followed by number, is a method of specifically designating a standardized, integrated, assumed to be functional and unique version of a mechanical and/or electrical hardware product that has completed the design process and has been approved to be put into final production, as well...

, the standard issue service pistol

Service pistol

A service pistol is any handgun issued to military personnel.Typically service pistols are revolvers or semi-automatic pistols issued to officers, non-commissioned officers and rear-echelon support personnel for self defense, though service pistols may also be issued to special forces as a backup...

 for the armed forces of the United Kingdom, the British Empire

British Empire

The British Empire comprised the dominions, colonies, protectorates, mandates and other territories ruled or administered by the United Kingdom. It originated with the overseas colonies and trading posts established by England in the late 16th and early 17th centuries. At its height, it was the...

, and the Commonwealths

Commonwealth of Nations

The Commonwealth of Nations, normally referred to as the Commonwealth and formerly known as the British Commonwealth, is an intergovernmental organisation of fifty-four independent member states...

 from 1887 until 1963.

The Webley is a top-break revolver

Revolver

A revolver is a repeating firearm that has a cylinder containing multiple chambers and at least one barrel for firing. The first revolver ever made was built by Elisha Collier in 1818. The percussion cap revolver was invented by Samuel Colt in 1836. This weapon became known as the Colt Paterson...

 with automatic extraction. That is, breaking the revolver open for reloading also operates the extractor

Extractor (firearms)

An extractor is a part in a firearm that serves to remove brass cases of fired ammunition after the ammunition has been fired. When the gun's action cycles, the extractor lifts or removes the spent brass casing from the firing chamber.-Overview:...

. This removes the spent cartridge

Cartridge (firearms)

A cartridge, also called a round, packages the bullet, gunpowder and primer into a single metallic case precisely made to fit the firing chamber of a firearm. The primer is a small charge of impact-sensitive chemical that may be located at the center of the case head or at its rim . Electrically...

s from the cylinder

Cylinder (firearms)

In firearms terminology, the Cylinder refers to the cylindrical, rotating part of a revolver containing multiple cartridge chambers. The cylinder revolves around a central axis in the revolver to bring each individual chamber into alignment with the barrel for firing...

. The Webley Mk I service revolver was adopted in 1887.