KS-23
Produced by Tula Arms Plant
The KS-23 (Russian: Карабин Специальный-23, romanized: Karabin Spetsialniy-23, lit. 'Special Carbine-23') is a pump action shotgun manufactured by Russian company Tula Arms Plant. The KS-23 was developed by TsNIITochMash in the Soviet Union for use by the Ministry of Internal Affairs. It is officially designated as a carbine in Russia because it uses a rifled barrel. The KS-23 is renowned for its large caliber, firing a 23 mm shotgun shell, equating to 6.278 gauge using the British and American standards of shotgun gauges and approximately 4 gauge using the current European standards (based on the metric CIP tables), making it the largest-bore shotgun in modern use.