Near the end of the 18th century, the first smokeless gun powder was invented. In 1898, John Rigby, a noted London gun maker, took a popular deer hunting cartridge of the day to experiment with this new powder. John Rigby removed the 480 grain bullet, tipped the black powder out, and replaced it with the new smokeless powder. The result was stunning. A deer hunting rifle became an Elephant rifle in one stroke. The name NITRO EXPRESS appeared from this first experiment in 1898. The new smokeless powder came from a nitro base.

At the same time, British Rail introduced a new train called the "Express Train". It too was a revolution. The papers were full of "Express Train" speed records. The new rifle was named the "Nitro Expess Train Rifle". After a few years, the train rifle part was dropped leaving "Nitro express". It is the heavy double rifles and cartridges developed by the English Gun Trade to stop the charge of dangerous game in Africa we call NITRO EXPRESS today