It is your choice. Depends on if you want to touch the rifling, if possible, or get need to get the bullet closer to the rifling. I'd say load a dummy round and do some measurements. Maybe work up some loads and see if it will shoot.
Wyatt's mag box does require some minor machining. Have done it with a dremel tool in two SA rem 700s but it was slow going. I'd also say that you could have issues with feeding, might need a different follower or perhaps some ramp work if you seat bullets longer, you never know.
I just suggested you try the factory magazine arrangement with a hybrid and if it doesn't work to your satisfaction get the Wyatt's mag box. I have one on my post 64 model 70 for a 300 RUM when I used to shoot accubonds. It feeds just fine with original follower. Can't say the same for my 6mm-284 in a SA Rem 700, need to do some changing to make it perfect.