I would add 1 thing gang.
I do my runs at full throttle. I only miss if I screw up my calibration for whatever reason...
At full speed badguys are less likely to climb and catch you you just have to adjust your delay accordingly....not gonna give away specifics..;o) Just make sure to level out far enough in advance to allow you to reach max speed, with doors open of course.
If I miss my target it is usually because I calibrate before I reach full speed and my plane continues to accellerate after calibration.
Can you say......LONG! With 1 Lanc formation you can destroy all hangars at a medium field. I've only been level bombing seriously for a few months and I'm having a ball!
Lancs do the most damage on the ground but other bombers defend themselves MUCH better!
My 2cents.