Agree with Joe. A barrel which bursts from use of too powerful a shell will burst in the chamber area. Once you get past the chamber area & it bursts the causes are the very rare structal flaw in the integrity of the steel & the much more common obstruction.

To borrow a phrase from old Ivory soap commercials, about 99 & 99 one hundreths percent of "barrel" bursts will be found to have had something in them. That .01% will have had some form of material flaw.

Miller/TN
I Didn't Say Everything I Said, Yogi Berra