Going with the comment "Go Big or Go Home", I would have to recommend my 6.5mm Allen Magnum based on the 338 RUM case .
My wifes 1K rifle will throw the 142 gr SMKs out at 3550 fps with relatively comfortable loads and do so with 1/2 moa accuracy.
Just need to keep the barrel cool.
Probably not what your looking for. She can be a bit finicky and very limited in powder selection. Still if your looking for shear HP, hard to beat!!! A 142 gr SMK loaded to +3500 fps is a pretty flat shooting round.
If you want a high volume shooter, I would not recommend it!!!