I beg to differ from "conventional wisdom" about the value of multipule loading manuals. Speaking as one who is closing towards my first five decades of reloading and owner of at least two dozen reloading manuals and two or three times that many powder company "freebies", I don't think there is anything but curosity value in a noob having more than one manual if it's a good one. And they all are quite good really, so the ABCs and one manual is plenty.
First thing to understand is that all loading data is generic by powder type and bullet weight. It is not Biblical so it is NOT necessary to precisely duplicate the listed load by a bullet maker or powder maker if for no other reason than they biggest single change we can possibly make to a book load is the weapon it will be used in. That "change" is THE ireason book loads vary and our guns are different from any of theirs; we have to live with that difference safely. It can easily be done but recognizing that loading manuals are no more that guides for both powder charges, AND OAL, is the first step, NONE of them are infallible in any respect.
Understandably, noobs - and a lot of older loaders - get puzzled by the fact that no two manuals will give the same start and max charges, or OAL, sometimes by quite a bit. So, what is the value of confusing data?
What books give us are the results obtained with their components and their rifle/handgun. If one book's suggestions are really "bad" for us and others are "good", should the loader average multipule book loads so it won't be so bad? NO! The major differences are in the guns used, not the data itself, so multipule books will give him very little real help!
There is ONE RULE, and only one rule, in every manual that takes care of all the possible variations in guns, chambers, bores, bullet types/styles, powder and primer lots, case maker lots, temperature, which way the wind is blowing, etc.
That rule is in every loading manual; "Start low, work up slowly to max while watching for signs of over-pressure. Stop and back off a bit if pressure signs do occur."
Do that and we can use any data in any rig with any changes of components quite safely without cross referencing anything. Those who ignore that one rule won't be safe with dozens of manuals.