Melting point of lead 327.46 °C, melting point of Iron 1538 °C. Additionally, I would assume that you have a lot less tolerances for bearing balls than for shot

Melting point of lead 327.46 °C, melting point of Iron 1538 °C. Additionally, I would assume that you have a lot less tolerances for bearing balls than for shot. So I assume that the much better process control for cold metal techniques is necessary for bearing balls.