Lapua Guy
My reasons why .375 weatherby over the H&H, RUM, or .378 Weatherby: 1) Personal limitations, I had to have my neck welded together a few years back, and my recoil tolerance isn't what it used to be. My H&H is pretty well retired, and about the the time I think I'm going to sneak it out friends make sure to borrow it. Some of the less sensitive among them will claim my love of big bores in my youth is the cause of my neck problems today. 2) The preference was one bullet, one situation only. I have shot a lot of 350's in the H&H and 2400-2450 fps is what you get. Barrel lengths 20-26 inches really not much difference. The 385 from what I can find will get to about 2225 fps. My experience with the Weatherby version tells I should get me back in the 2400 fps range. Not much for long range stuff, but enough to give me more confidence about a little expansion at Cape buffalo range. Just a little, and it's knocking on the bottom door of .416 performance. 3) The rifle I would convert is a Mauser with a 20 inch barrel built for close range heavy timber (Washington rain forest, swamps and jungles). I don't think opening this bolt face to Weatherby dimensions is a safe conversion, and the short barrel is not likely to benefit from a lot more powder capacity. 4) I could still fire H&H rounds if desired or necessary.
In reality other loads in the .375 H&H (especially the 350's) will work also. The 385 is something I was evaluating seriously but got stopped short of actually doing. It's an unscratched itch that flares up time to time.
And again It was an off topic answer.