Most of the significant wartime simplifications we see on rifles from World War Two are from Germany and Japan, but the rear sight of the No4 Lee Enfield is a good example of a similar action taken by Britain. By 1942, the finely-made milled rear sight assembly of the rifle had become a limiting factor for production, and something needed to be done. So in 1942 a very simple two position "L" flip sight was adopted as a temporary solution. While that allowed production to speed up, a better solution was being developed by BSA. Late in 1942, the Mk III rear sight was adopted, effectively a stamped version of the original. This became the new standard, and some rifles with Mk II flip sights were update din the field by unit armorers.