How do they make the lead pellets that go into shotgun shells?

Casting shot in molds has not been used for years.

Shot towers replaced the earlier techniques of casting shot in molds, which was expensive, or of dripping molten lead into water barrels, which produced insufficiently spherical balls. Large shot which could not be made by the shot tower were made by tumbling pieces of cut lead sheet in a barrel until round. Shot towers were replaced by the "wind tower" method by the end of the 19th century, which used a blast of cold air to dramatically shorten the drop necessary. Today the Bliemeister method is used to make smaller shot sizes, and larger sizes are made by the cold swaging process of feeding calibrated lengths of wire into hemispherical dies and stamping them into spheres.

The Bliemeister method is the modern method of making lead shot in small sizes, replacing the shot tower. Metered molten lead is dropped a very short distance (quarter inch, rather than 150-300 feet as a shot tower might use) into hot water or another hot coolant, and rolled along an incline underwater to round the balls. The temperature of the water is controlled according to the cooling rate, which depends on the size of the shot as well as the purity of the lead. Antimony, added for hardness, raises the melting point of lead.

Machines such as the "Incredible Shotmaker" allow hunters to make their own lead shot at home by the Bliemeister process out of scrap lead such as automobile wheelweights.

How do they make the lead pellets that go into shotgun shells?
They cast them with a mold. The link will help more.
Reply:A first they employed what was known as shot towers.

To day the technology uses force air and alleviates the need for towers.
Reply:they cast them in tiny molds in a factory
Reply:they use molds.......didnt you learn that in firearm safty class"