Well I really scrubbed the receiver up and I did find a crack!!! There is a pin down by the ejector and it is cracked there. The gun was really dirty with a ton of dried grease caked in all the nooks and crannys. This may be why it blew. My friend is going to make a repro USMC sniper from the parts and fit them to a good receiver.
Thanks for all the help,
Derrick
