An extremely large rifle, used for killing very large and very tough animals like elephants, dinosaurs, and Olympic weightlifters. They tend to run about .500 caliber or bigger. There are said to be .800 caliber elephant guns, but they are almost impossible for a single person to fire (and they say quite a bit about the too-wealthy and sexually-insecure individuals who buy them). For black-powder elephant guns, the balls can weigh upward of a quarter-pound. belgand says they sometimes use a nitro cartridge to add to the high caliber shell for increased penetration.

Of course, in Our Modern Technological Age, larger, more specialized elephant guns are now possible, including rifles that actually fire full-grown elephants! They are essentially artillery weapons, but they are quite effective in military combat. The destructive power of shooting an elephant into enemy troops is demoralizing enough, but in the rare instances in which the elephant actually survives... well, suddenly, the enemy has an angry, frightened, slightly singed bull elephant in their midst, which makes for a grand show. Unfortunately, the use of these guns is restricted, thanks to those damned animal-rights protestors.