I guess my question would be why do you want to spin the bullet harder than you have to? An 8 twist will work just fine for 105s in a BR. More twist just places extra stress on the bullet, causes more fouling, decreases velocity, etc. The BR needs all the vel it can get for 1K shooting as it is a little short on boiler room.
Take a look at successful BR shooters (the record setters) that are listed on 6BR.com and check out the twist on their bbls. I don't think you will see any 7 T bbls.
Just my .02 worth.
Bob