As Hondo and others have stated, if 85gr is the bottom end of bullets you're entertaining, I'd go minimum 1:8 - the 1:7.5 and 1:7 opens up more options beyond 105 (should you choose to tinker).

My .243 and 2 6mm Creedmoors are all twisted 1:8. (bullets - 95 LRX,105 Berger & 103 ELD-X)

[Linked Image from i.imgur.com]

WWP53D