I've done alot of research and see that almost everybody runs the 8tw but, seems this is just more of a "standard" that has taken over time. I know results speak for themselves but, I know some of you rifle loonies have results that I would love to have.
Hopefully chino69 will chime in, because if I remember right he was running a 7.5tw in a 6br but, I couldn't find his results.
Eddie Fosnaugh