Built for reloaders who demand both fit and function, Lyman custom fit loading blocks provide secure cartridge support during the loading process. Designed to accommodate families of similar cartridge sizes, each block holds 50-round in clearly labeled, precision-drilled holes. Made from durable polymer that resists wear and deformation, these loading blocks nest neatly together for compact storage. With six block sizes available, you'll find the perfect fit for your calibers - every time.