

These rejected barrels were deemed to be acceptable for the lower stress of firing slugs and less-lethal rounds, and thus were cut down in length for use as shotgun barrels.

The barrel for the KS-23 were made from 23 mm anti-aircraft gun barrels that were rejected due to manufacturing flaws. It was created by TsNIITochMash, a key Russian weapons developer, for the Russian Ministry of Internal Affairs (MVD). The KS-23 was designed in the 1970s for suppressing prison riots. It is renowned for its large caliber, firing a 23 mm round, equating to 6.27 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 use today. KS stands for Karabin Spetsialniy, "Special Carbine".

It is built from discarded anti-aircraft barrels, making it useful in long-range shooting and for firing various special-purpose shells. It fires the largest (realistic) shotgun shell in the game, 23x75mmR. The KS-23 is a Russian modern pump-action shotgun.
