Webley introduced their No5 Express New Army model revolver in 1878. This was essentially a ruggedized and scaled up variation on the No5 RIC revolvers that was very popular with police forces. The RIC was chambered for just the .450 Adams cartridge, and its ejection system in particular was not suitable to serious military campaigning. Hoping for a military contract, Webley took that No5 double-action clockwork and put it into a much bigger frame, capable of handling all patterns of British service cartridge as well as the American .45 Colt powerhouse. It then proceeded to lose the military adoption to the Enfield MkI, a frankly not very good design.

However, British officers had their own choice of sidearms, and many opted for the No5 Army Express, as evidenced by significant sales through the Army & Navy CSL catalog. The model was well liked and popular, but only for a fairly brief span. In 1887 the British adopted the top-break Webley MkI, and the development of new technology like smokeless powder and tip-out cylinders quickly rendered the No5 obsolete. But for about a decade, this was a very compelling choice, offering a reliably double action system with a powerful cartridge.