Hi Wall,

If my rifle I'd just leave it as a .375 H&H. I prefer reasonably low pressure, moderate velocity, and a nicely tapered case.

You could ask mikeH416rigby on this forum for his opinion, he has a rifle in .375 Ackley Improved, which is probably pretty much the same as a .375 Weatherby. He has used his .375 Ackley in Namibia for a variety of game and can give you details on performance.

Richard.