The Pattern 1913 Enfield (P'13) was an experimental rifle developed by the Royal Small Arms Factory for the British Army as a result of its combat experience in the Second Boer War from 1899 to 1902. The weapon was to serve as a replacement for the Short Magazine Lee–Enfield (SMLE). An advanced chamber design allowed for a high-velocity .276 Enfield rimless round, which was more powerful than the service-issued .303 British cartridge. Introduction of the P'13 was rendered impractical by the outbreak of the First World War. History During the Second Boer War, the British Army had been faced with expert Boer marksmen equipped with the Mauser Model 1895, in 7×57mm caliber. This experience prompted the War Office to develop its own "magnum" round in 1910, using a .276-calibre rimless cartridge. In August 1910, the Small Arms Committee, which had been responsible for the adoption of the Short Magazine Lee–Enfield, was asked by the Director of Artillery to produce a new specification for a service rifle. The main changes called for a Mauser-style action and a one-piece stock (a cheaper and more serviceable option). In response, Birmingham Small Arms (BSA) submitted a design chambered for a rimless high-velocity cartridge. In 1911, the Royal Small Arms Factory (RSAF) at Enfield, the British Government's design and production facility, produced a modified Mauser-pattern rifle for a similar cartridge, the .276. This rifle was presented to the Small Arms Committee on 3 April 1911 by the Assistant Superintendent Carnegie, and the Chief Designer Reavill. Initially the RSAF designed the new rifle, at this point the Pattern 1911, around two calibres; the .276 and the .256. The .256 was found to be inaccurate and the .276 was adopted in mid-1911 for further testing. Problems with pressure and jacket fouling in the bore resulting from the high velocity round led to the cartridge being redesigned. Numerous changes to the rifle and the cartridge led to eleven Pattern 1911 and Pattern 1912 rifles being manufactured. At the end of 1912, it was decided to put the latest incarnation of the design into limited production for troop trials in 1913 and 1,000 were ordered from RSAF. By the end of 1912, 508 rifles had been completed, and by the end of January 1913, 1,251 had been manufactured. The rifle was distributed to the army as the Rifle, Magazine, Enfield, .276-inch. The troop trial rifles left handed rifling twist