 About 1862 and later, W. E. Metford carried out an exhaustive series of experiments on bullets and rifling, and invented the important system of light rifling with increasing spiral, and a hardened bullet.The combined result was that, in December 1888, the Lee–Metford small-bore (0.303", 7.70 mm) rifle, Mark I, was finally adopted for the British army.The Lee–Metford was the predecessor of the Lee–Enfield.