Thought I'd share a bit of info now that I have a mates stock here. I had an identical issue on my laminated K98 stock (mines an Israeli 7.62 conversion)
Here are some pics that show what to look for if you're buying one of these rifles to save yourself greif later on or maybe help identify the issue in your own gun before more damage is done.
The best indicator of this issue is damage around the rear side of the cross bolt which acts as a recoil lug. It's also evident the action is moving rearward during firing when you find a gap at the front of the floor plate
As soon as you remove the action from the stock you'll find damage to the woodwork and maybe even a split
I'll help out my mate by doing what i did to mine. I'll carefully seperate the magwell a little with wedges, clean all the internal woodwork and glue with epoxy then clamp it all up tight. This should see it all lock up tight on the metalwork again. My rifle required the front and rear of the action to be bedded because there was so much damage to the timber but i think this one should be ok
Chronos