We can all thank the internet, social media, youtube for this because before this the best we had was to buy the ammo and test it ourselves because there is no way Guns and Ammo would ever have said something bad about Winchester Silvertips or some other ammo company that paid for ads in their rag.
Ammo companies have caught on and stepped up their efforts to produce better ammo because word is spreading fast as to what works and what doesn't. Creating ammo specific for certain barrel lengths helps narrow the best choices for gun owners instead of buying a box of .38 that the manufacturer tested and intended to be used with a 6 inch barrel being used in a snub is not a recipe for success.
Where this was most pervasive was people buying .22 Mag revolvers and JHP ammo that was intended for rifles.