David,

I think you are right about the smaller shell in the barrel. The ripping of the forward part of the rupture suggests more than just a blockage. I can imagine that the smaller shell detonated and caused additional damage.

It is great fun trying to over interpret visual data.

When do we get to find out what the real answer is?


_________
BrentD, (Professor - just for Stan)

[Linked Image from i.imgur.com]