I always go by the idea that a SD of close to 300 is desirable for big game. But as Aussie pointed out this is from the days when bullets were not as good now.

I asked Kevin Thomas the author of "There's Something about Buffalo" if he thought the 350 grain bullets upped the potential for the 375 H&H. He wouldn't go so far as saying they were better just that at least the 350 Rhino performed exceptionally well.

Have not used them but I would go 350 grains in the 40 calibers unless it hit a recoil threshold for me and if it did then I would drop back to the 325 or 300 grain bullets.

"When you disarm the people, you commence to offend them and show that you distrust them either through cowardice or lack of confidence, and both of these opinions generate hatred." Niccolo Machiavelli