Yogi, I believe you are right.
He put a lot of thought in the loads he chose.
In making experiments I would advise that you load not less than six shells just alike, taking care to mark them in such a manner that you will know just how they are loaded, and then load others with different charges in sets of six each, until you have quite a varied assortment... Then test them at the target, ... On no account should you have a preference for any particular charge. Let the targets settle the question.....When making these experiments, you should bear in mind that the barrel you use first should make a well-spread, even pattern at twenty yards, as in nearly all your shooting-in cover at least-your birds will be from fifteen to twenty-five yards when shot at...
As a rule you will find that the same amount of powder with a reduced quantity of shot will give more penetration and greater spread...
As a rule all guns that are turned out by first-class manufacturers will shoot well when they are properly loaded, and nearly all will shoot fairly well when loaded with almost any of the charges in common use; but "fairly well" is not good enough for you and me, and we will not rest content until we have found just the best charge...
He did carefully choose his loads.
Pete