on 17 june 1929 a prototype, along with technological documentation, was ordered from motovilikha plants. it underwent trials starting in october 1931, with two barrels of different construction, both fitted with muzzle brake. in may 1932 the gun was sent for improvements to the "no 38 plant", and it received that plant's designation "a-19". in 1933, three more prototypes were ordered from the barrikady plant in stalingrad and were completed in march 1935. the gun reached trials again in november 1935. after successfully completing the trials, it was adopted by rkka on 13 march 1936 as 122 mm corps gun m1931 (a-19).