NDZ M1 Garand M1 Carbine 1903 Muzzle Bore Wear Erosion Gauge Tool

Product Code: NDZ-GBT-M1

Manufacturer: NDZ Performance

Quantity in Stock

About this product+

M1 Garand and .30 Caliber Muzzle Bore Wear Erosion Gauge Tool

NDZ Performance Muzzle Wear (MW or ME) Bore Erosion Gauge Tool for M1 Garand, M1 Carbines and 1903 Rifles or most .30 Caliber bores - Stainless Steel. Our lasering process does not influence the diameter unlike other tools which can reduce your reading up to .001" showing a better bore than it actually might be. An original barrel showing .300" or .301 reading will bring much more value to a collector thus increasing the firearm collectability. Generally speaking, the muzzle will wear far greater than the throat. The M1 Garand has become a very HOT collectible rifle. M1 Garand Rifle Manufacturers included – SA (Springfield Armory), HRA (Harrington & Richardson Arms, IHC (International Harvester Co.), WRA (Winchester Repeating Arms). Trust the NDZ Brand, we have a solid reputation within the Pro 2A community with great parts and accessories and customer service to compliment it.

  • Brand NEW NDZ Tool - Fits .30 Caliber Rifle Barrels
  • Easy to use – the (00) is .3000" Tool measure bores from .2990 to .3025 (.303" is a general wear or service limit on a barrel)
  • Line increments every .0005" inch - high quality, everything you would come to expect from NDZ
  • Measures Muzzle Wear for Erosion the M1 Garand, & M1 Carbine M1A and others
  • Made proudly in the USA by skilled craftsmen
  • Lifetime Warranty against Breaking or Failure
  • NDZ custom laser engraved markings (does not add to diameter) - Easy to read!


Instructions:  Carefully insert, not to damage the barrel's rifling or the gauge, place the gauge into the muzzle as shown. Read the gauge directly from the side. Observe where the muzzle "falls" on the gauge.


  • 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

Note: NDZ always recommends any part be installed by a qualified and trained gunsmith. NDZ promotes the use of safety practices and gear when working on any firearm.

Product Features+

Manufacturer: NDZ Performance
Manufacturer Sku: NDZ-GBT-M1
Type: Tool
Country/Region Of Manufacture: Made In USA
Material: Stainless Steel
Color: Stainless Steel
For Gun Model: M1 Garand, M1 Carbine or any other .30 Caliber Rifle