The Webley-Fosbery Self-Cocking Automatic Revolver was an unusual, recoil-operated, automatic revolver

Automatic revolver

An automatic revolver is a revolver that uses the energy of firing for cocking the hammer and revolving the cylinder, rather than using manual operations to perform these actions...

 designed by Lieutenant Colonel

Lieutenant colonel

Lieutenant colonel is a rank of commissioned officer in the armies and most marine forces and some air forces of the world, typically ranking above a major and below a colonel. The rank of lieutenant colonel is often shortened to simply "colonel" in conversation and in unofficial correspondence...

 George Vincent Fosbery

George Fosbery

Lieutenant Colonel George Vincent Fosbery VC was an English recipient of the Victoria Cross, the highest and most prestigious award for gallantry in the face of the enemy that can be awarded to British and Commonwealth forces...

, VC

Victoria Cross

The Victoria Cross is the highest military decoration awarded for valour "in the face of the enemy" to members of the armed forces of various Commonwealth countries, and previous British Empire territories....

 and produced by the Webley and Scott

Webley and Scott

Webley & Scott is an arms manufacturer based in Birmingham, England. Webley produced handguns and long guns from 1834 to 1979, when the company ceased to manufacture firearms and instead focused on producing air pistols and air rifles...

 company from 1901 to 1915. The weapon is easily recognisable by the zig-zag grooves on the cylinder.
Semi-automatic pistols were just beginning to appear when Colonel Fosbery (1832–1907) devised a revolver that cocked the hammer and rotated the cylinder by sliding the action, cylinder, and barrel assembly back on the frame.