 The gun weighed about 2 metric tons and used fixed ammunition (case and projectile handled as a single assembled unit) with a 9.6-pound (4.4 kg) charge of smokeless powder to give a 54-pound (24 kg) projectile a velocity of 2100 feet per second (640 m/s).The ceiling was at the maximum elevation of 85 degrees.Useful life expectancy was 4260 effective full charges (EFC) per barrel.