The HP 100 round loading blocks are made from 6061-T6 billet aluminum. They are precision machined with holes going all the way through so loose powder falls out the bottom. We coat each block with a durable anodized red finish for easy cleaning and to keep them looking nice for years of use. The HP loading blocks are stackable for easy storage when needed. We offer the loading blocks in three sizes, 308, Magnum, and Lapua Mag.