The Sinclair Chamber Length Gauge helps handloaders determine the true chamber length from the bolt face to the chamber's neck end, indicating potential excess case length.
It is made of 12L14 soft steel to prevent chamber damage and comes with step-by-step instructions for repeated use.
There are limitations to the gauge's compatibility; the 30 caliber gauge does not work with 30-30 Winchester, and none are suitable for tight-necked chambers, except the G-243T.