How many 1,000 pound bombs would it take to shut down a factory? If I were to kill the radar factory, for instance, how many bombs, and how far apart would I need to space them?
The factories are large and require a lot of bombs. I found that I could get the ammo factory down to about 20% with the 12x1000 lbs loadout in a B-29 formation. And this with a very precise, manual (no salvo) bombardment and 3-4 passes dropping 3 to 4 bombs each pass.
The proper 'spacing' is best being learned by doing. You will get a feel for it while you are manually pickling bomb for bomb.
One way to learn it would be to go offline (or create personal arena), uncheck "protect objects", go to the airfield next to your sides strats and bomb them. That way you have very short transit time and no AA fire while you observe your bombing results.
If wanted, I could browse my films for some B-29 bombardment sequences.