Shell casing curiosity

[francis]

Hi All. I recently dug up a couple of these shell casings. This one pictured is the better example of the 2. What strikes me as odd is that it (the casing) appears to have somehow created a vacuum within itself. The firing cap appears to be intact, but if you look at the shell it has been totally 'sucked in' !!. Rather like a plastic wrap when a vacuum is applied around fruit, vegetables etc in supermarket packaging. The brass has only light cracking in it and as you can see it is completely drawn in around the tube up the middle as well. Im pretty impressed with it myself, but even more.....I would love to know how this has occurred. It doesn't appear to have been in a fire. Incidentally, can someone inform me of the correct name/term for the tube running up the inside centre of the shell? I look forward to any insight regarding this. Kind regards, Francis



[ATT

[CINDERSII]

Blast or concussion from a large explosion may have caused it, blast effects from ordnance have been known to do some pretty weird stuff

[carpediem]

It resembles exposure to enough heat to make it deform under it's own weight and gravity without being hot enough to liquify. I used to get similar effects in my youth by slowly moving discarded bottles closer to a bonfire. If done slowly enough, they collapsed into interesting shapes and could be placed against objects to achieve more varied shaping. This looks very similar with the draping effect and the tight form around the central rod. The cracks also seem to indicate heat damage. Just a guess, I suppose that there is no way to really know. Interesting find though!

[Gimmie]

it must have imploded in space!