That is always an issue. I use a lot of inherited powders from my old shooting friends that have passed on. I use loading data from the vintage of the powder's origin.There was the complete drop of Blue Dot for 125s but I had stuck brass with start loads under 158s so some of the data probably just wasn't compatible with current production lots
I've heard the same about Speer #8My first manual was a well-worn Lyman's 45, given me by my reloading mentor. I referred to it last night while looking for .357 Mag. cast bullet data.
Some of its listed powders are no longer available.
New powders have come on the market.
Some of its loads have been dropped in later editions.
Some of its loads remain in the latest edition.
There are those who have said its loads are dangerous. But, is there peer reviewed published proof that the supposed dangerous loads are really dangerous? Wives' tales? Myth? Heresy?