The busy guys over at Forgotten Weapons have got their hands on a pretty rare 1918 Farquhar-Hill semi-automatic rifle.  This early self-loading rifle went through several iterations by the inventor, Major H J Farquhar-Hill, including an automatic version and one with a recoiling barrel.  The gun adopted by the British in 1918 was a gas-operated rifle with a stationary barrel, but before production could gear up, the war ended and so did Britain's romance with the Farquhar-Hill. The rifle did find some use in the observer's seat in reconnaissance aircraft but that was about all. After the war, the rifle was redesigned into a light machine gun, but that didn't really go anywhere either.