Anti-aircraft defense aboard "Tashkent" was initially provided by six 46-caliber semi-automatic 21-K AA guns in single mounts as well as six DShK machine guns. The 21-K was a converted anti-tank gun with a rate of fire of 25–30 rounds per minute with an elevation range between -10° and +85°. The gun fired a shell at a muzzle velocity of . This gave them a range of . The DShK had an effective rate of fire of 125 rounds per minute and an effective range against aircraft of . The 21-K guns were replaced by an equal number of fully automatic 74-caliber 70-K AA guns in mid-1941. The 70-K gun had a