Other than a very few PH's, there are few people who are "experts" at shooting leopards. But my one cat, shot with a 250 gr partition from a .338, while spending a lot of time on a cruiser and in a leopard blind with one of those real experts, Nick Nolte, has given me an opinion.

In a fast .300 any relatively quick opening 180 gr bullet would be ideal. I say relatively, because too fast a bullet of too light construction can create a meaningful challenge for your taxidermist on a very expensive piece of hide. I think the 180 gr partition would be an excellent choice - and a far better option than the .375 - particularly with the 300 gr bullet. On my cat, that big partition from the .338 may still be going, so there was no recovered bullet to stare at meaningfully. However, the exit wound indicated that it had expanded a bit and likely acted like a normal SP rather than shedding its front end. That was typical on most of the antelope I took with it as well.
So were I going back for a second one, I would take my .300 WM loaded with 180 gr Accubonds, Partitions, are something similar.