I think you're good with a 1:7. I'm shooting a 1:7, principally with Berger 105 Hybrids, and it shoots well. The faster twist rate will allow you to get the maximum BC benefit from the longer 110 gr. and 115 gr. bullets, even though they may stabilize in a 1:8 twist barrel.
I'm also running a 1:7 in a 6 XC with velocities in the mid-3,100 fps range and have not had a bullet come apart on me yet.
Good luck.
Thanks for your help. Originally the barrel was going to be a 6x47L, but I purchased a prefit for that project. So I'm thinking I'll make this one into a 6 Dasher. Thanks again.