.5 inch Vickers Blank, Explosive & Tracer

As with the blank, no .5 inch Vickers explosive round was approved for service although considerable work was carried out in the late 1930s. It is likely that this was done to increase the effectiveness of the Vickers which even before the war was considered to be obsolescent as an anti-aircraft weapon due to the speed and strength of the aircraft likely to be encountered.One form of experimental explosive was based on the design of the .303 inch R Mark III and was known as the "R" type whilst the other was of similar design to the .303 inch B Mark V base fuzed incendiary. Neither were entirely successful in trials at Orford Ness and so did not enter service. The only surviving round from these experiments is an inert mock up with a flat nosed conical bullet. It is headstamped simply "23" and has a red fibre plug in the cap chamber. It is believed to date from the late 1930s.Later, special .5 inch Vickers explosive bullets were made for proof of the lead azide pellet for the .661 inch Vickers explosive round. The .661 inch was intended to be the repacement for the .5 inch Vickers anti-aircraft equipment in the Royal Navy but was not eventually approved for service.Right: Inert version of experimental Explosive round