Task: Question Generation
Input (English): Context : 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. 
Subject : DShK 
Relation : service entry
Output (English): In what year did DShK enter service?