First let me thank you for taking the time to explain and re-clarify.
So often these discussion degenerate into name calling and personal accusations - rather than a rational review of the facts.
I agree folks would do well to insure that their guns are well maintained and in good working order.
Also, it is both true and a good point that you have much more experience with your gun than anyone else has had.
When you pull the slide back that 1/16 of an inch doesn't the barrel just slide down the incline in the locking block?
Does it really move away from the breech?
The reason that I keep coming back to this point is that about a year ago I tried to make my G35 40 cal fire with a gap between the barrel and the breech.
I started with an empty 10mm. case.
It is the same diameter as my .40 but with a larger primer and is of course a bit longer.
I then got a Lee case trimmer.
I would put the case into the barrel and try to close the gun and get it to fire.
I could never get the barrel to even start up the ramp in the locking block - until the case was short enough to allow the slide to close completely.
Based on that experiment it just seems more likely and simpler that the pressure exceeded the case's strenght.
Especially since the failure occurred in the unsupported part of the case and not all around the case.
I dont know if you can try something similar with the 9mm.
40 club #137