NitroX - the .338 will do about 2,660fps with a 275gr. using H4350, an extremem powder.
: I seem to recall the Winchester factory 300gr. for it ran around 2,440fps, quite similar to the original .375H&H 300gr. factory Kynochs. of course, the 275gr. Speers and 300gr. Winchesters are no longer produced, but there are custom bullets available in these weights.
; The .338 is a find round inded, but I've never owned one, worked on several for friends and developed loads for them, but never owned one. I have owned several .375's in H&H as well as .375/06IMP's. I have seen little diffference on our game between the various .375's including my 9.3x62. they all seem to duplicate each others effects on game. You could probably add the .338 to that as well.
; I have a very good friend and hunting buddy, of 25 years, who has always had a .338 or three. For his guiding back-up gun, he uses a .375H&H, but packs a .338 while on his own hunts.