The Farquhar-Hill is a British automatic rifle.
The Farquhar-Hill was tested in May 1908, but was rejected due to it having a number of faults. Despite many improved designs following, the rifle never managed to completely satisfy the Small Arms committee. One example was trialed in the United States late in World War I. The British Army apparently ordered and adopted the rifle in 1918, but all orders were cancelled due to the war ending. In spite of this, it saw use with British aviators, along with Mauser and Mondragón self-loaders. In the 1920s and 1930s, Moubray G. Farquhar, one of the designers of the rifle, redesigned this rifle into a machine gun fed from top-mounted pan magazines; the machine gun was tested on a few occasions by the British Small Arms committee, but was also ultimately rejected due to multiple reasons.
The rifle uses a long-recoil action with a rotating bolt, with later versions using gas operation. The rifle had an "intermediate action" spring which stored recoil energy; upon discharge, the barrel would recoil back while still locked with the bolt, compressing the intermediate spring on recoil. Upon the return of the barrel to its forward position, the energy stored in the intermediate spring would cycle the bolt back and forth, extracting and ejecting the spent case and feeding a fresh round into the now stationary barrel. The main goal was to achieve smooth and reliable cycling, but the design was extremely complicated and thus badly suited for a military firearm. The rifle was revised in 1911, where the source of energy from barrel recoil was changed to more convenient gas operated action. The new revision also utilized an intermediate spring as a source of energy for cycling of the bolt, but the barrel was now made stationary, which simplified the design and made it potentially more accurate and reliable. The weapon had an unconventional bolt release; pulling the trigger when the bolt was locked back would cause it to fly forward and bring the first round into battery. The drum magazine had feed lips and a small switch which had to be repeatedly toggled when loading rounds into the weapon.