Task: Question Understanding
Input (English): Context : The weapon still fires 5.45×39mm ammunition from 30-round magazines at an approximate rate of fire of 600 to 650 rounds per minute, the barrel length remains the same and the muzzle brake has been retained, which suggests that the Vepr's ballistic performance should be identical to that of the AK-74. 
Question : In which year was the service entry date for Vepr?
Output (English): service entry