I don't know this for a fact, but I think a lot of the data in the older manuals is from the surplus 4831 that Hodgdon used to sell.
I remember buying a 50 pound keg of it back in the 60s, and I still have about a pound of it left.
Not sure again, but I think this was before Hodgdon started making it (or having it made), and before Dupont brought it out as IMR4831.
I am also not sure how the burning rates of the three would compare, but I doubt they would be the same.
New data in the loading manuals might vary from a little bit to a lot from the data used with the surplus powder.
This is not an answer to the original question. I am just including it as something to keep in mind when comparing new and old data and new and old 4831.
