Anyone have a front box dimension for a Wby?

I have a transition (H&H)long action and (H&H) long box (not the safari), which can go 4+1 with H&H and Win mags, but I can't get a fourth Wby down because of the shoulder. I can speed cycle 4+1 338 Win in that action and 3+1 with the Wby flawlessly. Just can't get the fourth Wby down.

Can that box be skeletonized? Can I split it up front to widen it? That rifle is in a HiTek stock and I have a layer of duct tape of give on either side of the box in the well.