The Lee 6-Cavity Bullet Mold blocks are machined from commercial quality aluminum and feature steel bushing and alignment pins. 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, 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, mold block halves are CNC machined for unmatched roundness and size control. Lee 6-Cavity molds come with a cam operated, hard-anodized sprue plate which is held tightly with tempered spring washers at each end. Weights given are Lee’s weights with suggested alloy; actual weight may vary due to alloy mixture used.