Small images on a thread inadequately illustrate what is usually very apparent on direct inspection, but
Chamber blow out without a ring bulge. Note no rib lifting
Another chamber blow out without a ring bulge; very localized rib lifting
Chamber blow out WITH a ring bulge, and rib lifting
I only play a metallurgist on DoubleGun
but:
SEM of the fracture edges in an obstructional burst show elastic deformation with ultimate cleavage.
Over-pressure burst show little elastic deformation with predominate cleavage."The general rule is that a chamber blowout is caused by excessive load, and that a burst barrel further up is caused by obstruction. The obstruction leaves a 'ring' of some sort."
That was Sir Gerald's position. Today however ANY burst, ANYWHERE is likely from "inexpert" chamber or barrel work
