Originally Posted by Drew Hause
Clearly an obtructional burst as evidenced by the ring bulge

[Linked Image from photos.smugmug.com]

The high tensile strength of the barrels, and wall thickness at the point of the obstruction, probably explains the generation of enough pressure to split the chopper lumps before bursting

[Linked Image from photos.smugmug.com]

Those are dovetail lumps. The Winchester version usually doesn’t look a whole lot better than that out of the box.

Photo lifted from Dewey’s website:

[Linked Image from i.ibb.co]
image hosting

Best,
Ted