In 1942 the British tested, and eventually brought into small production the Loen (London the city of design, and and Enfield, the location of the British Royal Small Arms Factory). Made by Major Reginald Shepherd who worked upon the Sten gun, and Col. Robert Howard a British officer who was injured in Tobruk as Operation Brevity went on.
Howard, who was injured fighting in Tobruk on May 15, 1941 and resting in London awaiting reassignment, wrote a detailed report of his units actions in the operation. One point he stressed, was the need for automatic fire, but also the need for long range ability. As he noted men with Enfield rifles where somewhat at a disadvantage in the narrow defense's of Tobruk, and also that the Sten gun had its one disadvantages due to the small caliber round, and range.
Major Reginald Shepherd, who put the S in sten, was interested in Howard's reports, and the two began talking. The two soon came upon the idea of an assualt rifle, and began working on designs. A prototype was created with a .303, selective fire weapon, that borrowed the Garand M1 double locking lugs, and unlocking raceway, that was created entirely out of stamped sheet metal. By September 1942 1,000 Mk. I Loen (or Lion as it quickly became know due to the loud roar the gun made a full auto), was issued to men in North Africa.
While the weapon was quickly asked for by many after the 2nd battle for El Alimin, Shepherd and Howard, a machinist before the war, worked to handle the overheating, and jamming problem the gun had.The Mk. II was sent out in January 1943, with a change to the reciever, and feed mechanism. The most recognized is the Mk. III which had a wooden handguard, and a detachable metal stock which some 2,000 where dropped before D-day to the French Resistance.
While never created in large numbers until 1944 when it became the standardized infantry rifle, the Loen did get a reputation as effective, and sturdy in the field. Following the war access to more material, and designers created a weapon that was considered the most modern, until the AK-47 became well know to the world.