1 - some haven't done fresh testing using improved powders.
2 - they continue to publish old data that satisfies traditional thinking.
3 - it costs a lot of dollars to produce an entirely new manual. Hornady still publishes data that goes all the way back to the 1980's! If anyone should bring loading data for the .35 Whelen up to date, it should have been Hornady with their constant introduction of "new" cartridges as well as ancient!
4 - as some here have said, the .35 Whelen will get the job done on most things (especially deer) at 2400 fps from a 250gr at most actual hunting ranges, being satisfied with that and willingly blind to the fact that 200 - 300 fps more from a 250gr makes it easily the equivalent of a .338 Win Mag with less powder, weight and recoil!
See my recent blogs on the issue of the benefits of expansion ratio.
