Well, as far as good for anything, guess that depends on your definition of good. With premium bullets of 350 grains some have reported (not me so I can't claim how valid it is) velocities of 2,300 fps or so. Should do the number on moose, bear, etc... 400 grain premium bullets are a little slower, around 2,000 fps from a 24" barrel. Not quite the 450/400, but respectable for North American hunting at close range.

The cartridge in the picture above does a tiny bit better, but not enough to really make a huge difference. It still doesn't exceed the 450/400 and it takes more pressure to get there.

What it does give is an easy conversion (though careful attention has to paid when cutting the chamber) for an '06 variant rebarrel. Rebarrel and no other changes have to be made.

If the rifle happens to be an '06 variant in the Winchester 1895 lever action, you can take advantage of the spitzer shaped bullets, something you can't do with the 45/70.