The 400 gr Woodleigh is the primary attraction of this rifle combination. Ruger shows the same 1-14" twist on their web site for both the .405 and the various .416s, so that's not going to be a problem, and if Ruger follows their usual practice the throat should be fairly long right out of the box. I don't usually get pumped up about smokeless powder guns, but this one ought to be a peach for buff with the right loads!