Flying Guns of World War II
Anthony G Williams has a particular interest in the history and development of machine guns, and their ammunition.  He is the author Rapid Fire, Assault Rifle [with Maxim Popenker] and the Flying Guns trilogy [with Dr Emmanuel Gustin], which describes the development of aircraft guns, ammunition and installations from 1914 to the present day.  He maintains a website at www.quarry.nildram.co.uk.