FYI, rifle is in PA.

 

I was studying my Carbines barrel and noticed the rifling was extremely poor. I read online that .30-06 M2 ball was an acceptable erosion gauge for the muzzle, but all I have on hand in 30 is 308 ball, x54r, 30 carb, random commercial or reloaded .30-06 and .30-06 Match. The match ammo protrudes maybe 1/4" when inserted into the muzzle. Is that good or bad?

 

I know I should go to the range, sandbag it, and see how it shoots. I can't find decent .30 carb anywhere though.\

 

IF it groups okay, I think I will just try to handload lead rounds for it, and maybe load up a few hundred hollowpoint or FMJ rounds for zombies or whatever (sarcasm).

 

If it shoots like crap, I will look at a new barrel. Commercial receivers are $500ish, commercial barrels are $200ish, USGI receivers are unobtainium and USGI NOS barrels are $600ish. I like that my Inland receiver matches my barrel, which is marked something like "INLAND DIV. OF GENERAL MOTORS 7-42" 

Nothing but a proper gauge is acceptable.... M2can give u an idea....but it is not accurate

 

Kind of disagree for bore erosion measured at the muzzle.

.308 is .308 no matter what the cartridge.

If you had a bore gauge for a Garand which is scribed at various points on the bullet starting at the ogive.

That would work fine on a carbine.

 

You can make a simple ogive gauge by taking a sized .308 case setting a bullet in upside down and marking the bullet.

Placing that bullet point first in the muzzle will give you a good idea of muzzle erosion.

For throat erosion I agree with Nick.  It can be done without a gauge but much more difficult.