Context : The Samozaryadnaya Vintovka Tokareva, Obrazets 1940 goda (``Tokarev Self-loading Rifle, Model of 1940'', Russian: Самозарядная винтовка Токарева, образец 1940 года) or SVT-40 is a Soviet semi-automatic battle rifle. 
Question : What was the year that SVT-40 entered service?
1940