I am just working up loads for my most recent project and have found H4350 to be producing better groups than RE 15 in my 6.5 X 47L. With BER 130 VLD(H) seated 0.010 into the lands with CCI BR-4 primers, 40 grs of H4350 is showing promise. My chamber has a .291 neck with 0.160 freebore.
When I chambered my first 6.5 X 47 a couple of years ago, I e-mailed Berger for load data and they responded with the data they had for their bullets with several powders at the time. You might give them a shout for up-to-date info?