"Pe-2 got even more defence starting from '179' series.
DAG-10 dispenser for 10 aircraft
grenades AG-2 was added at tail section. Despite those
grenades could not be aimed on the attacking aircraft, they could literally blast it of the sky."
from
http://209.85.135.104/search?q=cache...lnk&cd=3&gl=de
I will check my books at home and tell you if I find more!