Rastoff-I didn't do detailed examinations, but generally, the BCG had partially recoiled, the case was ruptured, venting gas into the mag well. The magazine internals and all remaining ammo blew out and the BCG wouldn't move. Most were cleared fairly quickly. It isn't uncommon for the extractor to get blown off the bolt, which was the case in the worst one I saw. One that one, we needed a brass rod and hammer to get the BCG moving so the case could be extracted and the upper opened. In that last case, the rifle was running the next weekend, so substantial damage seems real unlikely. I expect I discussed it with the owner, but that was .....decades ago.

Now, late last night it dawned upon me that what we might be discussing might in fact be caused by the bolt unlocking outside the design envelope (early).

The AR operates by differential gas expansion. It depends upon the bolt being fully locked and the gas pressure at the gas port being within a certain range. [The burn rate of the powder might also have some affect, similar to issues with the M1 Garand. The use of powders outside the Garand design envelope results in bent operating rods and other ills. Recall that the AR was designed & developed with IMR stick type powder.] If for some reason, the bolt isn't absolutely, completely rotated to full lock, the dwell time of the system will be affected (reduced). Now, add to this the possibility of higher than optimal/normal gas port pressure and duration of the pressure peak and you have the possibility of the bolt unlocking before chamber pressure has dropped to a safe level. Depending upon pressures within the BCG, it might happen with a fully locked bolt. Resulting in a ruptured case etc.

We've got no clue what powders Wolf is using in their ammo. Could be they've lately used a powder that's....less than optimal for the AR system.