The remains of the case appear to be painted all over the receiver. I had a case rupture in my Savage 110FP. It turned out my buddy was working up handloads for his 300 winmag . One of those loadings got in a 308 case. So basically, I touched off a compressed load . Fortunately, Savage had escape passages drilled in the bolt body to safely vent overpressure. It melted the extractor, ejector and firing pin tip. I told Savage customer service it was a handload. They said, no problem, those parts shouldn't fail, regardless. Asked if i was comfortable replacing them, or would I like to send it to a gunsmith. Savage took good care of me, but I'll never forget what the carnage looked like. Just like yours. I'll bet liquid brass got up around your firing pin as well. What does your boltface look like?