PLUS ONE to OD#3
There were probably very few "Aficionados" then. Except perhaps excepting the very wealthy. Guns were tools. Only the well healed could gather them as "toys."
Ammunition wasn't sold only in specialty gun shops. Ammunition was sold in every Hardware, General Store, Retail of every sort. Up on the shelf, ammunition was just that. Ammunition. If a rancher, farmer, hunter, traveler, whatever, needed ammunition, most likely, walked into the local purveyor of goods and pointed at the shelf and said, "Oh and gimme two boxes of them '44s." That was it. Nothing fancy.
The advantages of rifle and pistol shooting the same cartridge was already well known and appreciated. Popularized by the Henry and the 1866 being paired with Colt Ope Top and Conversions. The change to the 44-40 was just a matter course. Until the advent of the boxer primed cartridges, nobody reloaded, they just bought what they needed. Whatever they bought simply fed both Rifle and Pistol.