Does anyone have experience using either of these on deer or elk? I'm suspicious that the Hot Cor might be designed more for the 375 Win at MV of around 1800 instead of 2700. If so, they would be grenades in a 375 H & H.

The 235 gr Speer bullet was designed for the 375 H&H. I wouldn't suggest you use it on heavy or dangerous game but up to about 2900 FPS muzzle vel it holds together and penetrates very well. I would not hesitate to use it on deer ,elk pigs etc.

I've used both on deer and coyotes. No problems with either. The BC on the Speer is slightly better (.317 vs .270) so if 300 yard shots may be encountered the 250,270 or 285 gr offerings might be better as they will offer better down range performance.