As a collector of old load manuals, what I figured out is a bit of testing goes a long ways. Also a willingness to risk blowing up a gun helps!
I find Ackley's data is "enthusiastic" but seems to work in some of my guns. Some guns I have stopped early and some don't even get to the starting loads. You just have to try it and test carefully.
I treat it about like any data found on the web. Suspicious and to be tested carefully.