This thread and the following one remind me of what I went through deciding on my new Miroku/Winchester 1886 configuration. Lots of powerful cartridge options for a big, heavy 9.5 pound tough rifle.
Finally, I chose the ,45-90 chambering for these main reasons:
1. It shoots 450 grain .458 bullets at 2150 fps which places it well up in the class of African DG cartridges. It has taken ele and buffalo.
2. And, it handles commercial or hand loaded .45-70 ammo well when the biggest BOOM is not needed.
3. There is a wide variety of .458 bullets and loaded ammo available.
4. Modern powders and bullets provide the performance that formerly required a longer case and more powder.