Gary, Is the bolt in pic #3 still locked in battery? Is the firing pin tang aligned with the slot in the receiver?
I had my brother's Mini-14 blow up. Root cause was old ammo with neck splits. My buddies' 10 year old son was firing it. One round failed to fire for some reason, his dad racked it out and loaded the second round. Blew up because there was the first bullet still in the rifle, (2 bullets = blowup). The split neck allowed the bullet to be loose in the cartridge, it stayed in the rifle when he extracted it. The damage looks pretty much the same as the M1A, except only the extractor blew out of the bolt and the side wall of the receiver cracked. Luckily, the bolt stayed locked. the magazine blew out the bottom and the stock split lengthwise. The remains of the cartridge are stuck inside the chamber,( probably bulged it). Luckily the kid was not hurt, he said it kicked like a 30'06.
Majvret, Sorry for your loss,
were you wearing safety/shooting glasses when your accident occured?