The pressure is only "insane" if you don't have a good action and strong brass. I have Lazzeroni brass, fired in the McMillan MCR-T action he uses, that have been fired more than a dozen times (annealed after each 3 reloads) and the primer pockets are still tight.

Pay attention to the part about the good action as I think using the Rem 7 or Rem 700 for these is foolish as the bolt just isn't big enough in diameter to handle the bolt-thrust of that kind of pressure.

well thanks for the info... I was just going over cartridges in my head. My 378 is a wby with a stainless 27". I have oftan wondered why more havent played with say a 2.8" 416 based 375.

Take a look at the Dakota line of cartridges.

That's a fine cartridge, but a 3.34" on a 404. A bit different than a 2.8" on the 416.
There's probably a wildcat out there, seems everything's been tried.
Shorter cartridges (with same powder charge) mean more boltthrust, not to mention less mag capacity, so the trade-offs make less and less sense for a gun that'll pound so hard it needs to weigh a substantial amount. The benefits of a short action start to wane, if you know what I mean.