The .600 Nitro Express is a roun in the Nitro Express series which was introduced in 1903. It is the second largest caliber in the Nitro Express line, exceeded only by Holland & Holland's .700 Nitro Express round. It was developed for elephant guns, but most hunters felt that it was too powerful and harsh in recoil for anything but emergency use to stop a charging animal. Because of the larger cartridge, there was more recoil and guns chambered to fire the .600 were significantly heavier than those firing the .577 Nitro Express, which was already considered as being at the extreme end of manageable gun size and weight for a professional hunter.