Ramshot's data for the .257 is "modern," though it's of course limited to Ramshot powders (not a bad thing at all, as Hunter and Magnum both work very well in the Bob).
Nosler's data for the 100 and 110-grain bullets is good, but for some reason they don't include what I have found to be the best powders for 115 and 120-grain bullets.
If you can find an Alliant data booklet from a few years ago (mine is from 2005) there is some really good +P data, shot from a pressure barrel. But their latest data is all straight from the Speer manual, shot from a factory rifle that apparently has a loooong throat. The powder charges are semi-modern but the velocities are on the slow side.
