I have not used that bullet in a .375, but I think its's a good idea. I have used them in 285 gr. in the 9.3x62 and 9.3x74R to take a variety of game, at a variety of distances/impact velocity with perfect satisfaction. Quick opening, wide mushrooming, and deep penetration with very very good weight retention around 90%. The sectional density of a 285gr. 9.3 is identical to the 300 gr. .375, so I think there is good reason to think they would perform comparably.
They are my current favourite hunting bullet in several rifles and cartridges, not only my 9.3's. I have used the Oryx bullet in a variety of rifles / cartridges to take Giraffe, Kudu, and Gemsbok in Namibia, and Canadian Elk, Moose, Whitetail deer, Mule deer, Black bear, and German Wild boar. Never a problem of any sort.