My Tikka is 1:8, you will find high BC bullets are more accurate over all and much better long range. BC rules. 223 is a much better long range gun than either a 22-250 or 220 swift,(they average 1:10-1:14) as with the faster twist it handles heavy bullets better, how ever it is obviously not as fast. the 60 grain bullets are absolutely wonderful.
Carl
Now a fast twist barrely on a 22-250 is way cool but you get very short barrel life.
Carl