From Kagero "Me 410 In Combat"
Commanded by Maj. Klaus Haberlen, I./KG 51's baptism of fire took place on September 6th, 1943, when ten rocket firing Me 410's were up with the WGr 21-rocket racks suspended under their wings. The Germans set out to make contact with an American bomber formation that was flying to Stuttgart, and when in the Schwarzwald region, they encountered over 200 B-17's. Hptm. Winkel wrote later:
"For the several preceding years we had been bomber pilots who were expected to reach their target and drop our bombs there accurately. Now we were to fight using an entirely new type of weapon that we had no knowledge of, and neither did fighter pilots. We were to fight enemy bombers. We had no practice in aiming at targets of the B-17 type. So we flew closer and launched our rockets from a long distance. I could see the missiles flying fast forward and describing a ballistic curve. Dead silence fell on the radio - each one of us was looking what was to happen next. At some point a huge ball of fire blew up amongst the enemy formation, sending it down to the ground. I guess all of the pilots and radio-operators shouted of joy at one time because for a few moments I only heard one great shout!"
Not from Dierich's book.. faulty memory there!