Only problem with using a 308 dies is it, like an '06 die, tapers the body in.
I tried many dies and only one of my 260 AI dies has a body taper that does not squeeze in the body of a BR case while tightening the case at the .200 line.
Yeah, I've done the 308 die approach too and while it definitely sized the base of the case it pushed the shoulder forward a couple thou and made it difficult to bump them back enough.