The No. 5 Mk1 Jungle Carbine was designed for fighting in Burma and other terrain where the length and weight of the standard No. 4 Mk1 made it unsuitable. The No. 5 was about 100 mm shorter and nearly a kilogram lighter than the No. 4 from which it was derived. It began production in 1944 and had other unique features like a flash suppressor and a rubber buttpad to help absorb the increased recoil. It went out of service 1947, primarily due to its reduced accuracy, hard recoil, and the desire for semi-auto rifles.

This rifle has a length of 1 m, weighs 3.25 kg, and has a muzzle velocity of 600 m/s. Due to the large flash suppressor, it can only mount the No. 5 knife bayonet.