Sinclair International .257 Roberts +P/.338 Cal 40 deg Shoulder Bump Gauge Insert

Sinclair bump gauge inserts are designed to measure the shoulder bump when configuring full-length sizing dies. These bump gauges can be installed in either of our comparator bodies and are precisely machined to accommodate specific shoulder angles of cartridges. Instead of measuring to the datum line, these gauges provide a more accurate and easily accessible measurement by referencing the shoulder of the case, allowing you to determine the exact amount of sizing applied to your cases. It is ge