NDZ Performance Muzzle Bore Wear Erosion Gauge Tool for M1 Garand M1 Carbine M1A M1903 M1903A3 M1917 Enfield 30 Caliber in Stainless Steel
- Compatible with M1 Garand, M1 Carbine, M1A, M1903, M1903A3 & M1917 Enfield in 30-06, M2 Ball, .308 & .30 Carbine.
- 100% stainless steel construction, durable finish.
- Measures muzzle wear and erosion for .30 caliber bores.
- Easy to use and read: 0.0 indicates a .300 diameter bore, that is, .30 caliber, new, perfect. 0.5 is like new, .3005 caliber, Proper re-crowning will perfect the crown. 1.0 is excellent for a used barrel (.301 cal.), re-crowning should make it like new. 1.5 is good (.3015 cal.), proper re-crowning should make it excellent. 2.0 is fair (.302 cal.), proper re-crowning should make it serviceable. 2.5 is poor (.3025 cal.), proper re-crowning might make it serviceable. 3.0 or more, replace barrel..