Old data is fine, if you also have old stocks of powder.
Old Unique is different from new Unique, the newer IMR powders differ frrom the old DuPont IMR'S, etc.
The big problem is having older calibers that are no longer covered in new manuals, caution needs to be used in loading from old manuals with newer powders.
The only saving grace is the fact that the newer formulations of long time powders tend to be more consistant, lot to lot, than were earlier versions.
load safe !
NRA Endowment Member, NRA Certified Instructor for Rifle & Pistol, Illinois State Rifle Assn. - Life Member, GSSF Life Member,N.R.O.I. level I, IL Glockers #34
G: 19,20(x2),21,22,23(x2),24,27,29,34,35 & 36 (still counting)