Davis' design connected two guns back to back, with the backwards-facing gun loaded with lead balls and grease of the same weight as the shell in the other gun, acting as a counter. His idea was used experimentally by the British and Americans as an anti-Zeppelin and anti-submarine weapon[3] mounted on the British Handley Page O/100 and O/400bombers and the American Curtiss Twin JN[1] and Curtiss HS-2L and H-16flying boats. The direct development of the gun ended with the end of World War I in November 1918, but the firing principle has been copied by later designs.
The gun was made in three sizes: 2-pounder, 6-pounder and 12-pounder; 1.57 in (40 mm), 2.45 in (62 mm),[4] and 3 in (76 mm) in caliber respectively, firing 2-pound (0.91 kg), 6-pound (2.7 kg), and 12-pound (5.4 kg) shells. The 3-inch gun carried a pressure of 15 tons per square inch (2,109 kg per cm2) when fired.[5] Usually a Lewis machine gun was mounted on top of the Davis gun's barrel for use in sighting and as an auxiliary and anti-aircraft weapon.
^Trimble, William F. (1990). Wings for the Navy: A History of the Naval Aircraft Factory, 1917-1956 (1st ed.). Annapolis, Maryland: Naval Institute Press. pp. 35–36. ISBN0-87021-663-5.
Russell, Mark (2019). "Bring Out the Big Guns: British Military Aviation & the Development of the Heavy Cannon, 1914–39". The Aviation Historian (28): 60–69. ISSN2051-1930.
