RE: .270 SM?
Dan Im using Rel 22 with 130grn Nos Bt's out of my A-bolt. Im getting sub 1" 5 shot groups. It also shots the 130grn Barnes XLC's under an inch with max load or Rel 19 and Rel 22. It likes a bit of free bore with the Barnes bullets.
56grns for Varget and 110grn Vmax bullets shoot great also.
I have both and to me the 200fps advantage is worth it over the 270, especially if you handload.