Bill
I use a .458/300 grain Nosler partition. In my Omega and Remingtons I shoot it with a 110 grains of T7-2f. In the White and the DExtreme I shoot it with 120 grains of T7-2f.
I have only shot a few rounds with BH-209 - so I really can tell you much about that at this point. I have so much T7 I will not be making the switch anytime soon.