Ed,
What in the world would make you think that the receiver in question would shatter after casehardening? If you have read all the gunsmith manuals you claim than you should have at least walked away from the experience with a basic knowledge of metallurgy and principles of heat treatment which you seem to lack. Granted the majority of these manuals don't deal with the subject of bone and wood charcoal color case hardening very accurately, but than again, neither do you.

Regards,

Alex Johnson