Sir Joseph's adaptation of Bessemer's principle of hydraulic pressure casting was patented in 1874. The primary advantage of the “fluid compression” process was uniformity, and the absence of porosity and voids. There were several different Whitworth steels depending on the application, and his gun barrel steel did have a higher tensile strength than other steels of that period, but not of the gun barrel steels introduced in the 1890s. Lots of information here https://docs.google.com/document/d/1dnRLZgcuHfx7uFOHvHCUGnGFiLiset-DTTEK8OtPYVA/edit?tab=t.0