The shrapnel is 1/4 the size of a BB - they left it in because removing would have done more damage than leaving it in.
Imagine a BB. Cut it in half. Cut one of the pieces in half. You now have the shrapnel that still 'hurts' Kerry to this day.
Rigghhhtttt.
The partial filling I lost out of my lower molar 3 weeks ago is bigger than hanoi john's piece of shrapnel!