"Tashkent"s main armament was intended to consist of six 50-caliber B-13 guns in three twin-gun B-31 turrets, one superfiring pair forward of the superstructure and the other mount aft of it. However, the turrets were not ready in time so three single mounts were substituted. The manually operated mounts had an elevation range between -5° to +45° and had a rate of fire of 6–10 rounds per minute. B-2-LM twin-gun turrets replaced the single mounts in mid-1941. The B-13 gun fired a shell at a muzzle velocity of , which gave them a range of .