The Sinclair Shoulder Bump Gage Insert #25 is a precision reloading tool designed for 25 degree shoulder angles and cartridges from 225 Winchester to 338 Winchester Magnum.Sinclair Shoulder Bump Gage Insert #2525 degree shoulder angle measurementCompatible with 225W through 338W Magnum cartridgesPrecision machined for accurate shoulder measurementEssential tool for consistent case preparationPerfect for reloaders who need precise shoulder bump measurements to ensure proper headspace and consistent cartridge performance across multiple magnum calibers.