The overall quality of lead shot is always improved by the addition of plating. The plating process hardens the pellet and this allows for better patterning performance and enhanced . Plating also improves penetration capabilities of the pellet.
Copper-plated shot is manufactured in the U.S. by Lawrence. They plate their magnum lead shot to improve patterning and penetration.
Nickel-plated shot consists of a double-plating process: It is plated first with copper for proper adhesion and then it is plated again with a heavy coating of nickel. Nickel creates a less porous surface for unparalleled penetration capabilities.