When and if I get any more information, I will post an update. I know that the young man is now reading this thread, and the family thanks everyone who gave their thoughts. I think they will be taking all the pieces and parts to a competent gunsmith and then probably to an attorney here in Montana.
Thanks everyone.
Are you his attorney?
Why can't this young man make an account on this forum and answer some of the questions posed?
Is the bore or chamber currently obstructed?
Can we see the headstamp of the fired round when the action gave up the ghost?
Have you read majority of these posts? I sure in the ph uck wouldn’t create an account to tell this tale. Ph uck already have half guys theorizing it was disgruntled family member possibly an eco terrorist sabotaging ammo at the local gun shop. Now you want to see the headstamp of fired case when the gun blew up? Well that case still stuck in the chamber and their is no more headstamp..
You wouldn't necessarily need to see the entire headstamp and if you zoom in on the picture of the chamber supplied by the OP, it does appear there may be some stamping still visible on what's left of the case head. The resolution is not sufficient enough to tell. If there is a number or a letter present that is not in the 7mm Rem Mag headstamp, that could explain it. If the stamping indicates 7mm Rem Mag, that rules out some possibilities, namely that he picked up the wrong cartridge from another source.
That said, I certainly understand why they'd be hesitant to share any more details.