You can use any bullet of the appropriate caliber in either one of them...each will show you what it preferes...my 243 shot 55 grainers fairly well...and shot 95graines real well...my first 270 would shoot all bullet weights real well...and I'm waiting on parts from Brownells to see how my recently aquired 270 Ultra-Comp shoots...and I have bullets from 90 grains to 160 grains to try out...
Mac