Were the original 40X actions larger in diameter than the standard 700 action? Or was the increased rigidity just a function of not having the "hole" in bottom of the action for the magazine?
there were different 40X version not that long ago.
the XB was a solid bottom, the XC was a repeater with a clip charging guide, etc.
I wasn;t aware that any of them actually had thicker receiver walls as posted above.