Good sharp pictures, exact diameter, and exact weight are essential to analysis of such an object. If you would post those here, or email them to me, I'll see what I can tell, and/or get someone else involved who has more knowledge of ordnance of whatever era it appears to be from.
The possibility remains that it is some object other than ordnance, as we've encountered many ball mill balls, shotput, etc. that the owners thought to be ordnance.
You can send to: email@example.com if you don't know how to post the information here, and I will post it for you so others can see it.
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