Apparently, judging from this article, ball bearings have a longer effective range from the center of the blast of an IED or missile warhead than nails or irregularly-shaped metal shrapnel.
Witnesses in Israel reported a deadly radius of 450-600m from the missile warheads lobbed in by the Hezbollah this summer.
The relatively small Claymore mine (with just 1.5 lbs. of C-4) introduced in the Vietnam era could propel 700 spheres causing injury out to 250m, and death out to 50m.
Shaped projectiles which would naturally assume a nose-forward orientation might have even more range. Surely somebody has or is studying this. Or, it's already been ruled out as impractical.
NOTE: A-C-E does not make any bombs or IEDs. Nor does it encourage or condone such activities. This is merely to satisfy a matter of curiosity, based on the earlier post showing Humvee damage. And, the bad guys already know this.