Off center shell cavity.

[XRdsRev]

Pic 1 shows two fragments of 6.4” shells.  The fragment on the left is a typical example from Fort Fisher.  The fragment on the right however has a severely off center shell cavity which resulted in a great discrepancy in shell wall thickness.  I assume this shell was very unstable in flight.

Pic 2 shows the fragments stacked for additional perspective.

I eyeballed the “off center” fragment back in the late 1970’s when roads were cut through Redoubt (Fort) Dutton on the Bermuda Hundred Line.  I assume the fragment is from a Confederate shell but I honestly do not know who or where it was fired from.  Dutton is a long way from either the James or Appomattox rivers and I did not think the Battery Dantzler’s big guns could traverse that far inland.

[speedenforcer]

I too believe there may be some stability issues. But obviously it didn't effect its explosive abilities. It may not have hit the intended target but it probably still took out something.

[CarlS]

If you look at cut in half shells you'll often see this variance in the wall thickness.  They used a sand core to make the powder cavity and it had to be suspended while the molten cast iron was poured around it.  They seemed to move during this process to varying degrees.   If you look at the half shells you'll often see it not being centered.

Here is one on BulletAndShell.com that Mike is trying to find a home for that shows the core shifted right:
     http://bulletandshell.com/Items/item.php?id=F00326
This left a thinner wall on the right and a thicker ledge under the Bormann fuse on the left side.

Here are a couple already sold that also shifted:
Cannon Ball: http://bulletandshell.com/Items/item.php?id=F00282
Hotchkiss: http://bulletandshell.com/Items/item.php?id=F00166