Seems to me over the last 10 years or so it been the trend. Guys hunting deer with 223's, elk with 243's ect.
What's your opinion are we using lighter calibers than in the past to hunt North American game with?
Recent trend? I don't think so...been around for years.
The 7x57 and the 30-30 were around before the turn of the 20th Century.The 6.5 Swede not long after that,along with the 256 Newton,250 Savage,the 270 Winchester(killing everything from brown bear down since its inception)...the 257 Roberts in the 30's.The 6mm's were wildcatted in the (what,50's?) and gave us the 243 and the 6mm Remington,the 6.5 Rem Mag.The list goes on.
A guy named Sheldon was killing sheep and grizzlies with 6.5's in the early part of the 20th century;others named Caldwell and Corbett were killing tigers in Asia with the 250 Savage and the 7x57, to say nothing of the tons of African game up to elephant size killed with the 6.5's and 7x57.
All these cartridges and more were in widespread use(world wide) by the late 1960's. Most of the modern numbers hawked on the Internet today do nothing ballistically, than many of these older cartridges,and are nothing more than redesigns of these and other cartridges that were in widespread use and existence before the Internet was invented.
What has changed are better bullets, propellants,and much better and more advanced scopes....more abundant and cheaply made (affordable) rifles and actions to house the shorter rounds.
But people running around dusting grizzlies and elk with 243's and the ilk, is really nothing new.If you like to experiment along these lines, you're covering really old ground.People have been doing it for decades before.
