Im just going by what I see when I look at some of the older manuals, and with a number of them, the older "beginning" loads, are now considered to be on the hotter side of the data, and in some cases, middle of the road loads, are now past "max".
Same bullets, same powders. What changed? Differences in the powders over time? Differences in how they measure things?
Most all the later manuals seem to be on the lighter side of things when you compare them to the older manuals.