This Armstrong gun was the first rifled barrel gun in 350 years and was designed to replace the 68pdr muzzle loading smooth bore guns in Royal Navy service up to that time. It proved more accurate than the 68pdr on the range but was not successful in service conditions. When Vice Admiral Kuper bombarded Kagoshima in 1863, 28 accidents were reported out of 365 shots. The type was withdrawn in 1864 and relegated to coastal defence duties, to be replaced in the Royal Navy by 7in. muzzle loaders.