 On 1 January 1936 RKKA possessed 506 guns of the type, of them 422 operational, 53 waiting for repair, 28 used for training, 3 unfit.When RKKA received large numbers of more powerful 45 mm guns, many 1-Ks were apparently relegated to training facilities and depots.The exact number of 1-Ks in service in June 1941 has not been determined.