Those of you who have/use these two models need to periodically check the breech bolt - specifically the top/front and along the upper extractor recess for any crack that you may see..
Just had another one in yesterday with a cracked breech bolt. It's a somewhat common problem, which is why a replacement is hard to find AND spendy.. Second one I've had in since mid-'16..
The customer came in with a jammed-up action. The 'link' had broken (item between the bolt and the action tube follower). I got it apart, replaced the link then noticed the breech bolt's cracks.. Not good - certainly not safe.
So - just a word of caution for those who have these.. Check that area every so often and if you see something like the above - STOP using it..