BobinNH has been running 250 gr Bitteroots for quite some time in a 375 H&H. I don't recall the data he sent me but I have been trying it with 250 GR TSX's also. I believe the powder was H4350. I need to look at my notes and get back. Might be a good starting point for you fellas.

JOC was right. The 270 Winchester on a Model 70 is a great combination as is the 30/06 and 375 H&H