In my opinion, installing a cross bolt in your 6mm Mauser would be a waste of time. The 6mm don't recoil nowhere near enough to where a cross bolt would be needed. Just do a good job of glass/pillar bedding and don't worry about it. A quality glass bedding job will eliminate all play in the action/stock-thus the lack of need for a cross bolt.
Sometimes you earthlings REALLY amaze me!