That's sort of where I'm stuck. I'd like to be able to shoot the 90s if I wanted to but at the same time I never see them around. I also don't want to end up blowing up bullets with a 1:7 or even 7.5. I plan to make this a 26" barrel so it'll have the speed, I guess that should be another concern of mine.My 1:8 twist 22-250 AI (very similar capacity) can handle 55-88 gr bullets extremely well. My current favorite load is an 88 gr ELDM over RL-23… out of a 22" barrel it's a comfy 3150 FPS. If you're planning on sticking with bullets around 70 gr, then I would go with a 1:8.
I have a prefit 22 Creed barrel waiting for the 22-250 AI to burn out. This time, I went with a 1:7.5 twist for the Creed. It should do well up to the 95 SMK (or at least that's what I was told by several 22 Creed shooters).