NOTE - THESE ARE REPLACEMENT SIZING INSERTS FOR M-SERIES DIES. DO NOT BUY THIS IF YOU DO NOT ALREADY OWN AN M-SERIES DIE YOU WILL NOT BE ABLE TO USE THE ITEM.The Area 419 Zero M-Series Die Sleeve and Mandrel Kit provides modular replacement components for your existing .308 Winchester M-Series reloading die system. This kit delivers the same precision engineering that made the ZERO M-Series Dies revolutionary in headspace control and case sizing.Area 419 Zero M-Series Die Sleeve & Mandrel Kit for .308 WinchesterOne sizing sleeve identical to internal sleeves in complete diesOne mandrel delivering approximately 0.002" neck tensionOne extra decapping pin includedCompatible only with existing Area 419 M-Series diesPerfect for serious reloaders who want backup components or need to service their M-Series die system. Maintains the same reamer-cut sizing chamber precision and full-length ground mandrel quality as the original complete dies.