I would not hesitate to choose the 416Rem!
Mine is built on the M70 and is fairly light and quick handling following advice from Phil Shoemaker to sort of duplicate his personal light rifle. I think he built three; one for his guide, one for his daughter and one for himself. The 416Rem is a great cartridge from distance shots on medium sized game all the way up to effective stopping power on things that can hurt you. It's not a pure stopping cartridge like a 458, but it is more flexible. I'm of the opinion it covers the same ground as the 375HH while adding more power on the upper end.
As for accuracy, I�m loading Rem brass w/ 350TSXs and RL-15 to a decent velocity and am able to shoot groups just under an inch square at 100yards with iron sights. With scope, it�ll shoot small groups out as far as I need to send a bullet. A well balanced 416 in a good handling stock results in an outstanding rifle with very manageable recoil, even when in a fairly light package.
Best:)
