Hello Gentlemen:

I am not an expert, but I will expose my opinion.
I think that the probabilty to ocurr 2 ring bulges at the same event (one in each barrel with a double discharge) is very small.
Why not to think that the problem could be "overpresured" shells?
The shoter was concentrated in breaking clays and he do not notice that his shotgun start to develope bulges in the barrels, then, when the last "overpresure" shot was fired, the barrel finally burst.
Well, please forgive me if I am wrong.
This theory could be easy verified if there are some left shotshells from the same lot/box.

Best,

Last edited by Jose Fernandez; 06/03/16 03:51 PM.
Jose M. Fernandez