I have done a lot of thinking about what occurred. While I don't think that the metallurgy was as good as it should have been, I don't think that caused the problem. ( If you remember the receiver where the barrel screwed into had indications of Martinsite, or better known commonly as Crystallization.) It is possible that the explosion that blew the gun up changed the molecular structure enough to give it a cross grain appearance. I am convinced that there was excessive pressure.
I sent twenty five loaded bullets to Hodgdons Powder company for testing. 10 at 37 grains of H380, 10 at 35 grains of H380. ( the load that the gun came apart on.) and four that were packed to the brim with the same powder, and the bullet crammed down into the case. None of them were capable of causing enough excessive pressure to cause the gun to come apart.
Now one can safely assume that Savage would not admit that their gun was faulty, but the visible evidence that there was excessive pressure, in that the bolt gave way and the powder blew the primer out of the case and the gun apart. I did not falsify any of the information that I provided, so keeping all that in mind there is only one other thing that might have caused it.
The bullet that I was using was a Barnes Varmint Grenade, which is a "frangible" bullet, in that there is no lead in it. It is made with fused copper chunks that are intended to blow up as soon as they hit anything. I had shot several of them before, but when I loaded these rounds, I made a change in procedure. I normally use the loading data OAL (overall length) for which ever bullet I am using. This time I loaded the bullet long so that it was supposed to be just off of the lands of the barrel. I then pushed it back a bit more to where I was sure that it was not pressed into the lands and grooves of the rifling. I used a "magic marker" to color the bullet to check to see if it was back off the rifling.
It is my thought that the bullet was closer than what I intended and because of its "frangible" construction came apart in the barrel, causing the pressure. Hell who knows? Any way I guess I will shoot it tomorrow and see what happens.