The 23mm [0.91"] round having a belted bottle-necked brass cartridge case with the length of 150.5mm [5.93-inch] was intruduced by the Soviet Union in early 1940s and it was used by the high-velocity 23mm VYa aircraft gun. The gun had been designed by A.A. Volkov and S.A. Yartsev. This new 23mm cartridge was much more powerful than the 20mm rounds used by some aircraft guns from WW2. The “Ilyushin IL-2 Shturmovik” heavily armored ground-attack aircraft [nicknamed the “Flying Tank” by the Russians], the “MiG-5” escort fighter and some “Lavochkin” fighters were armed with the gas-operated belt-fed 23mm VYa gun which could be used with good results against lightly armored tanks and vehicles and to some extent even against enemy aircraft. The main purpose of the deadly 23mm VYa gun was tank-busting. In 1941-42 there was a project to rearm the Russian T-60 light tank with the 23mm VYa aircraft gun. The shortage of 23X152B ammuntion and unsatisfactory State trials resulted in the project being cancelled. Another project was to mount a 23mm BT-23 aircraft gun [also known as MP-6 gun] on the T-40 light amphibious tank but the plan never materialized. Also in 1941, an extensive plan to arm some Russian aircraft with the 23mm MP-6 gun [a modified MP-3 gun] was unsuccessful and finally ended. Before being modified, the 23mm cartridge used by these experimental guns [MP-3 and MP-6] was almost identical with the powerful 23X152B round. During the last year of WW2, electrically powered twin and quad mounts using the 23mm VYa aircraft guns were used on a very limited scale on some Russian torpedo boats or similar vessels. The WW2 23X152B cartridge was slightly modified and starting with the early 1960s was used by various Russian 23mm light anti-aircraft guns [23mm ZU light AA gun, ZU-23-2 which mounts two 23mm 2A13 gas-operated fully automatic AA guns or the self-propelled air defense gun version ZSU-23-4 “Shilka” having quad mountings]. Today the 23X152B cartridge [which uses a steel case] is still in use in some parts of the world. — NOTE: I selected the above text from my article named “The 23X152B Cartridge Case”, article published by the IAA Journal this year. Orita 12/05/05
Do NOT confuse the Russian 23X152B belted cartridge with another Russian 23mm cartridge which is the 23X115 round having a bottle-necked rimless case with a length of only 114.5mm. As I mentioned above, the 23X152B belted round was used during WW2 by the poverful 23mm VYa aircraft gun. Starting with the year when WW2 ended, the 23mm VYa aircraft gun was replaced by the NS-23 [Nudelman-Suranov] light aircraft gun. In late 1940s, the Russians introduced the NR-23 [Nudelman-Richter] fast firing aircraft gun. Both these 23mm aircraft guns [NS-23 & NR-23] fired the same rimless 23mm cartridge, the efficient 23X115 round. Other Russian 23mm aircraft guns developed later [AM-23, GSh-23, GSh-6-23] fired the same 23X115 round. Orita 12/09/05
