How to perform Lag Displacement Roll Attack?

[jameson]

Watched some US propaganda footage on utube yesterday showing our boys beating the Luftwaffe, lots of gun cam footage. What struck me is that the victims never moved, made no attempt at defence even with tracers wizzing by, even before they were hit. German footage shows pretty much the same. WW2 pilots seemed to fire from further away, 250 to 400 yards. There's much in Jumo's point. The weapons seemed to be a lot more effective than they appear ingame as well.