Webley-Fosbery automatic revolver

.455 caliber Webley-Fosbery revolver, left side

.455 caliber Webley-Fosbery revolver, right side

Diagram from original US patent granted to Col. Fosbery for design of his automatic revolver; Upper frame is in forwardmost position.

Diagram from the same patent, showing upper frame in recoiling position. Note that the gun in the picture uses different cylinder rotation mechanism when compared to production Webley-Fosbery guns.

Data for Model 1902 Webley-Fosbery revolver with 6 inch barrel

Type	Double Action semiautomatic revolver
Caliber(s)	.455 British Service or .38ACP
Weight unloaded	1065 g
Length	267 mm (10.5")
Barrel length	152 mm (6")
Magazine capacity	6 rounds (.455) or 8 rounds (.38)

This unusual weapon, which combined features (either good and bad) of both revolver and a self-loading pistol was a brainchild of British Colonel G. V. Fosbery. The basic design was conceived during last years of 19th century, and first production guns appeared from noted British gun-making company Webley & Scott in 1901. The Webley-Fosbery revolvers were widely tested by various armed forces, but never adopted because of over-complicated design and insufficient advantages over either a double-action revolver (like contemporary Webley & Scott revolvers) or early self-loading pistols. Webley-Fosbery revolvers were produced in several modifications up until start of World War One, and it saw limited action in Boer wars, as well as in WW1 in the hands of few British officers who purchased it privately.
Webley-Fosbery revolver, in fact, had few advantages over contemporary revolvers of same caliber - mostly those were reduced recoil (because of recoiling action and heavier weight) and somewhat improved accuracy in rapid fire (because of self-cocking action and reduced recoil). Its mechanism was quite sensitive for dirt and fouling, and gun must be held tight during the fire, or otherwise the recoil movement of the upper frame will be insufficient for cycling the action. Its reloading was not much faster than of contemporary revolvers, despite the fact that special flat clips were developed for this weapon, holding either 6 .445 or 8 .38 caliber rounds at once.

Webley-Fosbery revolver used recoil energy generated by each discharge, to rotate the cylinder and cock the hammer for next shot. To be able to do so, it had a two-part frame. Bottom part consisted of a grip with trigger unit, and has rails on its upper surface. The upper frame, which held the cylinder and tip-down barrel, as well as hammer unit, as able to recoil on the lower frame rails against a spring. Upon recoil, a special stud, fixed on the lower frame, followed the zig-zag tracks in the cylinder to rotate it and index next loaded chamber with the barrel. At the same moment, hammer was cocked. Once all ammunition in the cylinder was expended, revolver was reloaded by pushing on the barrel lock release and swinging the barrel down on its hinge, thus tipping the rear of the cylinder up. This movement activated the automatic extractor which pulled empty cases out of cylinder chambers simultaneously. Once cylinder was emptied, fresh cartridges were loaded (either one by one or all at once, by using a flat steel clip), then barrel was swung up and locked. After reloading, revolver could be fired either by double action pull on the trigger, or by manual cocking of the hammer with subsequent single-action trigger pull. Webley-Fosbery revolvers were also fitted with manual safety levers, located on the left side of the grip frame.