I vote .243 Winchester.
I have a .204 and it is the best for prairie dogs at <300 but the wind moves that little stinger a foot easily in a normal Wyoming day.
I started varmit hunting with a .223 but wanted some more speed so along came the .204.
I switch back and forth depending on the day but have killed more coyotes with the .243.
Bullet technology hasn’t really moved much in the last 50 years. You want high horsepower Roy Weatherby already has a round for you.
You want the latest trend the 6.5 whatever and the .204 Ruger are the darlings.
you lost me on your bullet technology comment