help identifying 57mm projectile?

My great-grandfather somehow acquired this shell during the war, it has his name "A.J McNeal" and the date "July 1943" on it. Not sure if he served, when or where, could have brought it back, or been given to him. But what is it? 57mm dia, about 12.25 in long, and weighs exactly 20 lbs.

 

Maybe something here:
48-57 MM CALIBRE CARTRIDGES
or elsewhere on his site at:
BOOKS BY ANTHONY G WILLIAMS

 

It appears to be a 57mm M1 AT round, originally a 6 pounder. Why it weighs 20 lbs, I have no idea, the bottom seems to be filled with lead or some other metal, as it is completely solid.

 

Its not an AT round, that's for sure. It is definitely an HE round with that open nose. The fuze isn't fitted. The stamping is also odd. This is done on the obturation ring. That is, the ring that seals the round in the gun barrel rifling when fired.

I suspect that it was lead weighted and sat on someone's desk for a while as an ash tray or converstation piece and that the name stamp is not original to the shell.

 

While it does appear to be an HE round, the M1 57mm HE round wasn't issued until around June 1944, well after the inscription date.

Things that make you go: "Hmmmmm."

 

I will give a website that deals with a large historical base of shells and ordinance (mostly small but not limited to that for sure) of different kinds and it may take a while to get to the things you may want but if you are a collector of such things you may already know of this site: International Ammunition Association but I will add some information for those who like to look over these items. If it has been professionally demilled it cannot be remade into a usable round again without some metallurgy being done to it. If it has not been professionally demilled you may have to be carefull as there are lots of nooks and crannies that may yet hold energetic materials in sufficient amounts to do some damage. It has been proven by many accidents that the above is true as many troops may have taken some of these apart and were not trained for those nooks and crannies that may have been there to anchor the energetics. I just want all who appreciate these things to do so in a careful way at all times to be safe with the historic items.