Thanks for all the comments guys, and I appreciate the post from DickD at McMillan. To be clear, I'm SUPER happy with this stock and have it shooting good now. A quick bedding job will solve any other issues after my grizz hunt, but it took very minimal work to get everything working as needed. About 15 minutes with a file.
Dogcatcher,
I was curious about the mag box being loose, as mine is quite loose. Thought it would cause me issues and rattle, but works very nicely.
I havent owned a Ruger in a while and bought this one for a grizz gun. My other rifles are both Remingtons and obviously not quite as 'finnicky' with adjustments. Even still, I do like the utilitarian feel of this M77 in 338WM. Should kill a grizz well enough!