The potential barrel qualities of steel were well known in the mid nineteenth century but also a major barrier to its practical use was the inability to produce blanks of suitable quality without internal flaws. In 1869 Sir Joseph Whitworth developed a process of compressing fluid steel into ingots which in effect squeezed out these flaws and resulted in a solid bar. This development began the steady decline and then disappearance of pattern welded barrels. My question is when did the production of Whitworth steel barrels end? I am aware that by the late 1800's considerable competition had begun. Is anyone aware of Whitworth marked barrels after World War 1?

John McCain is my war hero.