TEST OF 20MM MOUNT MARK 10, WITH OERLIKON MODIFICATIONS

Abstract : Tests were conducted to determine the comparative performance characteristics of the Oerlikon-modified and standard Mk 10 20-mm mounts. The modification consists of spring mounting the gun in the cradle and changes in the firing mechanism. With standard barrel springs and standard ammunition, the modified cradle increased the rate of fire by 53 rounds/min. With standard barrel springs and Oerlikon ammunition, the increase was 135 rounds/min. The Oerlikon ammunition fired on the average about 100 rounds/min faster than standard ammunition with the modified cradle. The highest rate of fire was 635 rounds/min, and was obtained with the modified mount, modified mechanism, standard barrel springs, and Oerlikon ammunition. The average muzzle velocity of 22 rounds of blind-loaded, traced Oerlikon ammunition was 2971 ft/sec; the time of flight to about 1000 yd ranged between 1.26 and 1.33 sec. The Oerlikon modifications to the 20-mm mount and firing mechanism also decreased the characteristic vibration.