Lyman custom fit loading blocks are engineered to deliver a precise, secure fit for a broad family of cartridge sizes. Each block is crafted from rugged, impact-resistant polymer and holds up to 50 cartridges - perfectly arranged for efficient reloading sessions. Available in six different sizes, each block is clearly marked with hole diameters for fast identification and reliable performance at the bench. Stackable, nestable, and built to last, these blocks are the smart solution for reloaders who value precision and order.