Forster Products Full Length Sizing Die Features Diamond stoning process enlarges the inside dia. to prevent over-sizing due to thick neck walls. Useful for brands of brass cases with thicker neck walls or when you do not intend to outside neck turn case necks that have thickened after repeated firings. Forster Products Full Length Sizing Die Specifications Manufacturer: Forster MFG Product #: 005291 Reloading Caliber: 6mm XC No more than .008a ^2 stock removal from your existing die neck diameter is possible. Honing is done in increments of one half thousandth of an inch (.0005a ^2) meaning that your specified inside diameter must be either .XXX0a ^2 or .XXX5a ^2.