Both guns were in service with the 471 Siege Battery RA in France, the “Boche-Buster” in the Arras sector and the “Scene-Shifter” in the Bethune area. These pieces made more than 200 shots in 4 months of deployment, including the so-called “King’s Shot”, made on August 8, 1918, when the “Boche-Buster” lived up to its name by making a direct hit on the Douai railway station from Mareuil, at 30 km distance, in the presence of His Majesty King George V.The guns had a recoil of only 864mm at maximum elevation and had a traverse of 4º on each side by sliding the end of the mounting across the front truck bolster. In addition, a curved track was used to obtain larger arcs of fire. A 30 hp Siddeley petrol engine drove a generator to provide power for the ammunition hoists, but the rest of operations were done by hand.
