Lyman's upgraded sizing dies now incorporate a 90-degree hole spacing configuration, dramatically improving lubricant distribution, especially when working with modern, hard bullet lubricants that traditionally resist flow. The die's tapered mouth guides each bullet smoothly into the hardened steel interior, ensuring optimal alignment for a perfectly cylindrical finish. Internal dimensions are precision-calibrated to match the recommended sizing diameters across a wide spectrum of popular pistol and rifle calibers. To prevent deformation during the sizing process, Lyman top punches are CNC-machined to mirror the specific contour of the bullet nose, ensuring concentric alignment and preserving bullet integrity. Refer to the sizing chart to select the proper die for your caliber. Constructed with high-grade hardened steel for maximum strength and resilience The tapered mouth design improves feeding and reliability in your firearm 90 degree lube holes facilitate optimal lubrication for smooth mechanical operation Compatible with RCBS punches for versatile reloading options