The Sinclair Chamber Length Gauge helps handloaders determine the true length of their rifle's chamber to avoid over trimming cases.
It is made of 12L14 soft steel to prevent damage to the chamber and comes with step-by-step instructions for repeated use.
Specific limitations apply: it's not suitable for thin-necked or tight-necked cases, and should not be used in handguns or certain rifles like semi-automatics, lever actions, and pumps.