Federal

Hotchkiss

Federal Hotchkiss shell

This example  is a case-shot variety of the Hotchkiss pattern.   Hotchkiss patented on April 28, 1863, patent #38,359, an improvement employing an iron plate, to prevent the mixture of the case-shot balls and matrix with the bursting charge.  This arrangement caused the case-shot to be thrown forward with greater velocity when the projectile detonated.  Go here for a complete specimen.