Thanks for the replies, I don't use mods though, and the servers I fly on may not allow that specific mod anyway.
"use BombsightTable2 for IAS-TAS conversion and then input the accurate data into the OP-1 bombsight through in-game interface rather than dropping on a preset angle"
Do you mean use BT2 to figure out the TAS, then ignore the angle BT2 gives and just line up the two needles on the sight? Unfortunately this does not always work, hence my problem from my first post. Different sizes of Soviet bombs do seem to fall differently, I think you found this yourself when you added different correction angles for the big bombs (BB) and medium bombs (MB) in your guide. But the OP-1 always gives the same angle given the same altitude and speed, regardless of the bomb size. And there also appears to be variation from plane to plane (Pe-2, IL-4, Pe-
