Georgy Semyonovich Shpagin worked with Vasily Degtyaryov on a gun that fired what size cartridge?
Georgy Shpagin:  He is best known as the creator of the famous PPSh-41 submachine gun, as well as working with Vasily Degtyaryov on the DShK heavy machine gun. DShK: The DShK 1938 (ДШК, for Дегтярёва-Шпагина Крупнокалиберный, "Degtyaryova-Shpagina Krupnokaliberny", "Degtyaryov-Shpagin Large-Calibre") is a Soviet heavy machine gun firing the 12.7×108mm cartridge.
i don't know