The Ishorsk factory built the BA-27 between 1928 and 1931 based on the AMO F-15 truck chassis. However, these chassis were not suited to carrying the heavy armour and later versions were built on the three axle Ford Timken truck chassis. These variants were designated BA-27M. There were 193 in service on 1st June 1941 just before the start of Operation Barbarossa. The BA-27M's main armament was a 37mm gun with a 7.62mm DT machine gun. Its main role was for scouting and infantry support.