Brownells Barrel Chamfering Plug Gauge 11deg-18deg 38/357 Caliber

There is a very narrow, (.004'''') throat diameter range where maximum accuracy is obtained. Go smaller or larger and accuracy will suffer. By simply slipping the Plug Gauge into the barrel throat, it's possible to tell at a glance when you are approaching the correct diameter. Warns you before you go too far. Also valuable as a diagnostic tool for guns brought in with accuracy complaints, (designed for chamfers cut with our tools - may not give a correct reading on guns with other degrees of chamfer). Each gauge is self-piloted, precision-ground, hardened and stepped to show minimum and maximum optimum diameters. 11deg and 18deg Gauge measures both chamfer angles. Sizes .22RF; Mfg: Brownells SPECS: 1 1/4'''' (3.2cm) long. Steel. Instructions included. 11deg-18deg gauges measure forcing cones with either angle. 5deg, .38/.357 gauge is designed for Ruger .38/.357's which began using this angle about 1983. Complete Set includes the Rimfire Gauge, all ten Centerfire Gauges and Instructions in