put the 156 in a 6.5 creed and it's fine, or a 77gr in a 22 creed. You can even get factory 22-250s with an 8 twist to shoot those heavy bullets. The only factory offering that I'm aware of that could utilize that Berger you referenced would be a 6.8 western. If you could stick that Berger in a 270, is the throat long enough to not kill your powder capacity?
I have seen some folks build 8 twist .270s that were killer with the 170. I think that the .270 is generally marketed toward people who want off the shelf ammo availability and not people who build custom rifles that are purpose built for long, heavy bullets. I'm glad you mentioned the 22 creed though, because that has been on my radar. The only thing keeping me from doing it right now is that I have a 6 creed that I can just load lighter bullets in. I haven't been down that rabbit hole enough yet to see if there is an advantage either way.
If you want custom you could build whatever to shoot whatever. The 270 is like the 25 cals. Until the last few years options for high bc bullets have been non existent. There are a few options, but with the sammi spec of the 270 and 25-06 you can't utilize those bullets.
