If you fancy yourself as someone who has a quick trigger finger, Operation: Confederate is just for you. If you can manage to hit more enemy vehicles than any other player on your team over the next few days, you'll net yourself an additional 750 XP! The Operation starts at 03:30 PST January 7, 2013 (11:30 UTC) and runs through to 03:00 PST January 11, 2013 (11:00 UTC).
Here's more details about the Confederate badge:
Hit more enemy vehicles (at least 6) than any other player on your team. These enemy vehicles must subsequently be destroyed by another player. If two or more players score an equal amount of hits, the achievement is granted to the player who earned more XP in the battle, including additional XP provided to Premium Account users.
Experience is the life-blood of a tanker, and the best part of Operation: Confederate is that it's repeatable; you'll get this reward every time you meet the above criteria as long as the event is active.