Quite probably, and it'd probably be cheaper too; ball bearings are kinda precision things and the processes that make things like gravel or nails probably cost

Quite probably, and it'd probably be cheaper too; ball bearings are kinda precision things and the processes that make things like gravel or nails probably cost less. That said, if someone was really set on creating the opening scene of the movie Swordfish, they could make those ball bearings deadly if they got them going fast enough. A 3/8" ball bearing moving at a few hundred meters per second has enough energy to fuck up persons and property. I didn't pick those numbers completely at random -- 3/8" is about 9.5mm and common 9mm handgun rounds have velocities in the 300-400 m/s range. Edit: I want to call attention to other replies to this comment pointing out that ball bearings can be good shrapnel for other reasons I'd not considered. Today I learned a thing.