So got a break today and enough time for a range trip to try some 87 gr VMAX in my new BHW 6x6.8.
Used 8208 XBR, 2.265" COL, CCI BR-4, HDY brass:
28.2 => 2940 fps ave, 7.8 sd
28.4 => 2954 fps ave, 14.0 sd
28.6 => 2962 fps ave, 28.6 sd
28.8 => 2974 fps ave, 6.7 sd, next best group (0.63")
29.0 => 2981 fps ave, 6.7 sd, best group (0.42"), and 1717 ft-lbs @ muzzle
primers still looked good, minor flattening, no craters, and still 100% AR function.