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. 11° and
18° Gauge measures both chamfer angles. Sizes .22RF;
.32; .38/.357; .38-40/.40; .41; .44; .45. 5° Ruger-Style
Gauge available in .38/.357, .44 and .45 caliber
only.
SPECS: 1¼" (3.2cm) long. Steel. Instructions included.
11°-18° gauges measure forcing cones with
either angle. 5°, .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 a Bench Kit Box.
Catalog page 488