Sinclair Bump Gage Inserts are precision measuring components used to determine shoulder bump during full length resizing. Instead of measuring to the datum line, these inserts reference off the case shoulder to show how much you are actually sizing the case shoulder. This helps you dial in resizing and keep brass and loaded ammunition organized when working with multiple rifles chambered for the same cartridge.
Key Features
Designed to fit Sinclair comparator bodies for bump measurement
References shoulder bump off the case shoulder for a more direct measurement
Variant machined for a specific cartridge shoulder angle and caliber class
Helps improve consistency when setting up full length sizing dies
Useful for verifying separation and dimensions between brass and loaded ammunition
Get a bump gage insert matched to your cartridge’s shoulder angle for easier, more repeatable setup of your sizing workflow.
