Lyman MSR Ammo Checker Block Black. Their black anodized finish matches your favorite "black" rifle. Check the quality and consistency of both loaded rounds and purchased ammo. A must for any AR shooter. You can?t afford mis-feeds so get the easiest ?Go? gauge available for modern sporting rifle calibers. Covers 223/5.56 6.5 Grendel. 6.8 Rem SPC 7.62x39 .30.0AAC Blackout .450 Bushmaster .458 SOCOM .50 BeowulfCNC machined to minimum chamber specsConfirm ammo will chamber smoothly Specifications for Lyman MSR Ammo Checker Block: Manufacturer: Lyman Weight: 3 oz Color: Black Fabric/Material: Black Anodized Features of Lyman MSR Ammo Checker Block: Covers 223/5.56 6.5 Grendel 6.8 Rem SPC 7.62x39 300AAC Blackout 450 Bushmaster 458 SOCOM and 50 Beowulf. CNC machined to minimum chamber specs. Confirm ammo will chamber smoothly. Package Contents: Lyman MSR Ammo Checker Block Lyman 7833003: MSR Ammo Checker Block Black