These cases are specially modified to work with Lock-N-Load Precision gauge. A special fine thread is used to attach the case to the gauge, ensuring it remains perfectly square for precise alignment in the chamber of your firearm. The neck of the case is made perfectly round and opened slightly to allow a standard diameter bullet to slip into the case mouth effortlessly, but concentrically, to ensure the most precise results possible.Specifications and Features:Type: Modified CaseCaliber: 6.5 PRCFunction: RifleMaterial: Brass