Double Cavity Round Ball Mold .530 Diameter by Lee Precision Product Overview offers the Double Cavity Round Ball Mold .530 Diameter. Lee mold blocks are machined from aluminum blocks making them rust resistant. Aluminum molds heat up and cool down faster than iron or steel molds so good bullets can usually be produced after only a few casts. In addition and they are one-third the weight of iron or steel mold blocks for less fatigue during extended casting sessions. To ensure the best possible bullets and mold block halves are CNC machined for unmatched roundness and size control. Handles included. Specifications and Features: Aluminum Mold Blocks Light Weight CNC Machined Handles and Sprue Plate are Included with Mold