Does anyone have photos of the plates used to contain a stand of Grape? (NOT cannister, GRAPE.) I have never seen or recovered such a plate, which make identifying this dug item a tad problematic.
Interestingly, it measures 4.5" so is consistent with a 12lb load. It was found behind well bombarded Confederate artillery positions (Schenkl and Hotchkiss shell fragments had also been found in this area in times gone by.) The square head bolt was found nearby the plate but not directly with it. This area was outside the range of cannister, but within probable grape range of Union positions.
Based on terrain and distances, the selection of a grape round for indirect "recon by fire" (to coin a modern term) would be feasible. Still, it could just be farm junk. I welcome more informed opinions.
Mike