I imagine billions of shots have been fired in guns joined similar to this one with no ill effects and we can only guess the pressures many have digested without even a burp. Millions of guns were made this way. So, Im going to say time has proven it to be safe. I keep looking at that dark area in the break up about 1 1/4 forward of the breech. I agree with others, it is dark and not consistent with the rest of the fracture. Could have been a crack that went unnoticed until it let loose with an exclamation point!

When an old man dies a library burns to the ground. (Old African proverb)