British experience in the South African War of 1899-1902 showed the need for a short rifle for universal use and even before the end of the war a new weapon had been produced and a thousand made for trials. It was also tested against the Mad Mullah in Somaliland, and after some modification emerged as the Short Magazine Lee Enfield Mark II in 1907.

It was an excellent weapon and although slightly less accurate than its predecessor it has certain compensating advantages, notably its easy breech mechanism which allowed a fast rate of manipulation. The British Army had concentrated on rapid fire to the stage where every soldier could fire at least fifteen well aimed shots per minute, and the devastating effects of this were clearly seen in the first few months of WW1 where the gallant German Infantry suffered heavily.

The Mark III was a complex weapon to make and in 1916 various simplifications were introduced, notably the abolition of the magazine cut off and the disappearance of the special long range collective fire-sight which was clearly unnecessary in the age of the machine gun. These changed its designation to the Mark III, perhaps the most famous rifle in British military history.

It remained an excellent weapon with an 18 inch sword bayonet for close quarter work and the ability to project grenades either rodded or from a screw on cup. Soon after the end of the war the British began to consider a new rifle, similar to its predecessor but easier to make by modern mass-production techniques. The first step in this direction resulted in a new Mark V rifle which appeared in small numbers as early as 1923. Apart from an extra barrel band near the muzzle its main difference was that it had an aperture backsight rather than the open U-type of the earlier rifles, experience having shown that this type of sighting was easier to teach, while the increased distance between the backsight and foresight reduced the margin of error and made for more accurate shooting.

In the end, however, it was decided that the conversion of the large existing stocks of rifles would be too expensive and although the development of a new rifle was maintained the British Army continued to rely on its well tried Lee-Enfield until well after the outbreak of war in 1939. The Mark V differed little from its predecessor apart from the fact that it was sighted to 1400 yards.