The most powerful double rifle I have shot was a 470 Nitro that I shot once. Have shot a few 375s but they are not a big bore. I don't like recoil and have no problem admitting this - if I won the lotto, my double rifle would be a 450-400 whose recoil I can take comfortably. I'd much rather shoot a lot more with a medium bore light recoiling rifle than take a few shots with a heavy kicker.

Cheers!