The Rifle No. 5 Mk I, was a derivative of the British Lee–Enfield No. 4 Mk I. Following experience of jungle fighting in the Pacific War, the British concluded “a rifle shorter and lighter than the standard issue, bolt action .303 cal No. 4 rifle was required. However, its operational use was in post-war colonial campaigns such as the Malayan emergency, where it gained its common nickname of the “Jungle Carbine.”
On 21 March 1944 the finalized design of the new rifle was approved. On 12 Sept 1944 the name of this model was officially changed to Rifle, No. 5 Mk. Production began in March 1944 and finished in December 1947.
The carbine’s features are:
The action is the same as the No.4 but has been lightened by removing steel in some areas.
The 20.5” barrel includes a pinned-on flash eliminator.
The rear sight is graduated to 800 yards, instead of the 1300-yard sight found on No.4 rifles.
The butt stock has a rubber recoil pad.
Production of the new rifle began at the Royal Ordnance Factories at Fazakerly and BSA Shirley. Although several thousand No. 5 rifles were made before 2WW ended in August 1945, the design was not used for combat much during the war. Production of the No. 5 rifle continued after the war. While the rifle was popular because it was shorter and lighter than other models, the complaints were the rifle could not shoot with consistent accuracy. The British government officially discontinued production at the end of 1947.