 His cartridge consisted of a percussion cap with a bullet attached to the top.Flobert then made what he called "parlor guns" for this cartridge, as these rifles and pistols were designed to be shot in indoor shooting parlors in large homes.Usually derived in the 6 mm and 9 mm calibres, it is since then called the Flobert cartridge, but it does not contain any powder; the only propellant substance contained in the cartridge is within the percussion cap.