I've seen split cases, separated cases, blown primers and set back bullets in AR platforms. Only time I ever saw any damage similar to this was from a slam fire / out of battery condition (not counting the pictures of the 300 BO fired in a 5.56 chambered rifle).
I'm trying to figure out how you can get a slam fire/out of battery when the firing pin can't reach the primer until the bolt rotates and locks into the lugs of the RE?
A bullet setback could cause the bolt to unlock and force the gas/pressure out the easiest route but an OOB firing is next to impossible unless the firing pin is out of spec or broken.
Slam fires have occurred but never resulting in a blown up AR like this.
Not trying to argue just simply going over facts trying to determine what happened.
