The Sinclair Chamber Length Gauge helps handloaders determine the true chamber length from the bolt face to the chamber's neck end, which can differ significantly from published trim lengths.
Made of 12L14 soft steel, the gauge is inserted into a fired case and chambered in the rifle, then measured after making contact with the chamber end, without damaging the chamber.
Not suitable for use with certain calibers and firearms, including thin-necked cases like the 22 Hornet and 218 Bee, or in handguns, semi-automatic, lever action, and pump action rifles.