Fisher Gauge muzzle wear gauge for M1 Garand, M1 Carbine or any other .30 caliber rifle barrel.
Measures from .300" to .303" diameter very simply and quickly.
100% made in USA from stainless steel with direct reading permanently laser etched markings.
Typically, when it gets up to .303" diameter its pretty well worn out, less than that depends
on how picky you are. Gage reads .30 on the handle and segments indicate last two
digits, for example .30 + 15 = .3015 diameter.