In 1942, the British government instituted a development program to design a new simplified rifle to replace the No4 MkI Lee Enfield. The CSAD (Central Small Arms Department) came up with a design using a quite simple receiver machined form a small steel billet. It was a rifle wholly distinct form the Enfield, although both were chambered for the .303 British cartridge. The simplified rifle used a front-locking bolt, a simplified cocking piece, and had a magazine holding just 6 rounds. The sights were a simple 300/600 yard rear aperture, and a crude spike bayonet could be fitted either forward for use or rearward for storage.

The project never got as far as serial production, or even field trials as far as I can tell, and only a handful of prototypes were made.