Berry's Superior Plated bullets begin as a swaged lead core. The plating process works through electrolysis as the lead cores are tumbled in an electrically charged bath containing high-grade copper ingots. The copper clings to the lead and the longer the bullets remain in the bath, the thicker the plating. Our bullets are plated to the correct size and then taken out of the bath. SAAMI Max Length - 2.260, Base Diameter: +.001 -.000.