Has anyone tried opening up a 700 Ti stock to handle a barrel as large as a magnum contour Remington?

no, but you could. i sold a couple a few months ago and they had enough meat to do it. They are actually pretty good stocks, though MUCH heavier than they should be for their intended purpose. I think the factory you could trin off 8 ounces with no problem. Does not matter on a sporter, but is a cardinal sin on a fly-weight