This thread makes me want to go out and get a decent 243 that I can work on/with for long range.
Plenty of good 6mm cartridges out there....
I'm old school..6XC & 6BR
Build an 8 twist barrel & go to town
https://www.accurateshooter.com/cartridge-guides/6xc/https://www.accurateshooter.com/cartridge-guides/6mmbr/