Barrel 280-mm mortars, Br-5 was developed under the guidance of plant Barricades Ivanova.
Br-5 has not been established, the plant launched its Barricades in gross production. Total in 1939 was commissioned 20 mortars and 25 - in 1940. In 1941, there was no one put a 280-mm mortars. After the beginning of World War II mortar Br-5 have not been done.
Four 280-mm mortars, Br-5 came in November 1939 in the 40th DAO OM. Since the beginning of the Finnish war, they passed their course 260 km to the firing position. Just the fighting was 414 shots, that is approximately 100 shots on the trunk. When shooting noted tight opening and closing of the shutter. Compressor threw the liquid through the packing case - the cause persists. At an elevation angle of 18-20 ° broke the iron supporting bar. During the Finnish War, no mortar Br-5 has not been lost.
22.06.1941, in the Red Army were armed with 47 280-mm mortars Br-5 (serial 45 mortars and two experienced mortars surrendered in early 1939).
explosive shells to Br-5 were designed before 1917 and intended for 280-mm mortars Schneider. F-674 and F-674K - old Russian grenades and F-674F - French.