The Sinclair Shoulder Bump Gage Insert #23A is a precision reloading tool designed with a 23-degree angle for accurate shoulder measurement on .25-270 caliber cartridges.Sinclair Shoulder Bump Gage Insert Model #23A23-degree angle specificationCompatible with .25-270 caliber cartridge casesPrecision machined for accurate measurementsEssential tool for consistent case preparationAn indispensable accessory for serious reloaders seeking precise shoulder positioning and consistent cartridge dimensions for improved accuracy and case life.