Sinclair International Shoulder Bump Gauge Insert #26A 26 Degree 6mm

The Sinclair International Shoulder Bump Gauge Insert #26A is a precision reloading tool for measuring cartridge case shoulder position. Its 26-degree angle and 6mm specification match the shoulder geometry of 6mm Remington cases, so the insert seats correctly against the shoulder for a repeatable reading.

Used with a Sinclair bump gauge system, the insert lets you check how far a fired case shoulder has moved and set your sizing die to bump it back consistently. That control over shoulder position supports reliable chambering and uniform case preparation across a batch.

Key Features

Compatibility

Fits Sinclair bump gauge systems. The 26-degree, 6mm specification matches 6mm Remington cartridge cases.

How to use

Install the #26A insert into a compatible Sinclair bump gauge, then measure a fired case to read its shoulder position. Use that reading to set your sizing die so the shoulder is bumped back consistently.