My 1885 low wall is a .260.
You can cover all those bases very easily with one, including elk.....mine has killed two so far.
I think a 6.5cm would be the best of breed for your needs, as you described them.
7-08 would be my next choice, but recoil will increase and it won’t kill any deader....
Those low-walls in 260 Rem are scarce as hen's teeth, and go for a pretty penny.
IIRC, Winchester is chambering the 1885 in the 6.5 Creedmoor, but they are hard to sneak up on!
ya!
GWB