The Martini-Henry rifles were produced substantially by hand, making the quality extremely variable. Though efforts were being made to phase out these rifles by the 1890s, some 9000 were still in service in 1906. In addition the .577/450 Martini–Henry cartridge was considered obsolete, though it was still in military production as late as World War I, and in commercial production by Kynoch until the late 1950s.
Therefore the Martini–Henry did see service in World War I in a variety of roles, primarily as a Reserve Arm, but it was also issued (in the early stages of the war) to the Royal Flying Corps observers and Zeppelin-buster aircrews, using an incendiary spitzer bullet. The spitzer was also effective against aircraft. Martini–Henrys were also used in the African and Middle Eastern theatres during World War I, in the hands of Native Auxiliary troops.