6.5 mm in a 260 rem .. 243 100 grain copper if you could find them would require a fastervtwist rate than a std 243 I think 85 I'd tge max in 6mm copper ?
Make a nice custom build though if you could get 100 grain ttsx , would maybe blow up light varmint bullets in flight though ?
Make a nice custom build though if you could get 100 grain ttsx , would maybe blow up light varmint bullets in flight though ?