I didn't get the double exp. for first battle of the day, and yeah I was with a guy in a KV-3, like a dragoon team, we were supporting each other, it often arrives that the KV-3 shooted the first shot and then 1 second later my gun was reloaded, so yeah thats why I get the Reaper trophy. A lot of the tanks I've killed (T6,T7 medium/heavy) need about 3-4 shots and in this 3-4 shots I always get 2-3 shots on it. On my 7 kills, only 2-3 of them I've killed all by myself, others by help of the KV-3 and others.