It would be a hard choice for me. The 416's don't do anything for me, I suppose because they are not all that unusual.
I've thought for a long while that I'd like to build a 404 on a left handed model 70 or Montana 99 action. I've also considered doing a 400 H&H on a left handed Remington 700 to match my 300 H&H KS Mountain Rifle. It would certainly be a two gun battery suitable for the whole world of big game.
I have a 400 Whelen so the need for either the 404 or 400 H&H would only be to satisfy my loonyism.
