is the 270 based on the same parent round as the 308 I cant rember? You might want to look at the 6mm ppc the 6.5 grendal or ppc the 6.8 rem spr. these all will fit in a 223 mag. the 6.5 grendal is the one that ,s got me thinking accurate at over 500 yards. the reamer is an issue however.