I will first say that I have never used a 375 on any thing........ Having said that I don't think an elk, moose, or bison, or even Grizzly,warrants the use of a 300 grain bonded bullet out of a 375H&H. A 270 grain soft nosed bullet would be my first choice here in NA. Much quicker expansion and shock to the animal and if a 270 grain chunk of lead doens't penetrate through a bison then that is one hell of a tough bison. That 260 grain acubond from DT ammo and Federallooks like a real winner as well.
Pretty sure off the bat I'm going to try Remington 300gr A-frames, and probably federal TSX, and maybe federal noslers, or trophy bonded.
If I were going after Cape buffalo, elephant, rhino with a .375 then these would be my first choice followed up with solids. Or if the H&H were capable of pushing270 - 300 grain bullets to 3000 fps and higher.But not on NA game animals and not at the velocities that the H&H produces. There's just no need to.