This is what is commonly called a "hospital bullet" or a "pain
bullet". It is a Minie ball dug at a hospital site at the Gettysburg
Battlefield. It has been chewed to where it is nearly unrecognizable by
one or more soldiers who have been wounded in battle in a manner that is
terrible to contemplate. So too is the bullet hard to look upon. To ease
the inherent horror I feel when I hold it in my hand, I have given it a
name different than those commonly used. I think of it as a "Comfort
Bullet" because it brought a bit of comfort to the poor soul who made
these teeth marks.
This bullet has far above average teeth marks, implying either unbearable agony or that it was chewed by more than one man. I prefer to think the latter.