View Full Version : Throat erosion on M1

December 12, 2008, 21:50
I looked at what appeared to be a near new H&R Garand last week. I have several, but considered buying this one if the barrel checked out better than the others I have. My H&R measures "1" on the gage and it will just about drive nails with Lake City. Every JC Garand match I`ve used it in it has brought home trophies....

Anyway, this H&R I looked at measured a "1.5" for TE. I know muzzle wear is a better indication of accuracy, but the TE will tell more about the amount of rounds downrange. This H&R was all H&R, no wear on anything, including the bottom of the bbl, bottom of bolt, hammer, and op rod spring. The only thing that was "wrong" with it was the mismatched Greek return stock. If I thought I could have found a "correct" stock for it I would have bought it($800+tx) for a collectible.

This months GCA magazine details a supposedly unissued Winchester M1 from WWII. In the data sheet, it shows TE=1.

What will a "new" barrel gage? The gage has a "0" on it, but I`ve never checked a bbl I knew was new. The best I`ve ever seen is my H&R that measures a 1.

(who sells a decent muzzle wear gage? CMP always says "on order", but I`ve never been able to get one. They`re always "sold out". I don`t think they`ve ever had any, LOL)

December 12, 2008, 22:36
I've seen muz. guages on gunbroker, Fulton Armory also has them.

Throat errosion is not really a good indication of how many rounds have been fired when you have a low number like 1.5. New GI ones can measure that from what I've read. And to help compensate for TE, if you're a reloader, is to seat you bullets out a little further.

December 12, 2008, 22:47
As I understand it, new-out-of-the-tube USGI barrels will measure anywhere from 0-2 for TE, before installation. If I wanted that rifle for a shooter, I'd be measuring muzzle wear.

December 13, 2008, 00:05
Originally posted by TerryN
As I understand it, new-out-of-the-tube USGI barrels will measure anywhere from 0-2 for TE, before installation. If I wanted that rifle for a shooter, I'd be measuring muzzle wear.



December 13, 2008, 00:29
I have a H&R M1 collector grade from CMP that looks unissued that has a TE of 2.5 and a MW of 1.5. From what I have seen that's not unusual.

December 13, 2008, 10:37
This FAL barrel is about as new as I have seen--I thought the gauge was
wrong or the barrel was not a 762x51 but it is a 762--just really unused.


January 08, 2009, 16:24
You have got to remember that guages that are built for M1s are built to read out on the specific bbl geometry for that rifle, and may not be accurate on other 30-06 rifles.

January 08, 2009, 18:33
GM4sd. TE gauges have to be rifle specific and read of the receiver ring not the barrel shoulder.

It is said above, new USGI M1 and M14 barrels can gauge TE at 0-2 when new. This is true (though I would pass on a 2 if I was paying for a new barrel but you are not )

Throat erosion is only an indicator of wear if you know where it started when new. Your 1 or 1.5 reading is great. A zeroed out gauge reading is is not the tell all.

I gauge and log all my US rifles when I get them. I have and HRA Garand went from 2 to 2.5 in about 800 rounds.

I recently gauged a brand new Criterion and it was 1+ at the throat and 1. at the muz. The gauges have variance in production too. Best practice is to observ erosion over time by logging your reading and checking after another 500 or 1000 rounds. As a general rule, non Chrome lined barrels will lose something you can measure in that time. For chrome lined barrels you really need to look at that throat because the chrome throat holds up to more rounds before showing the same gauge reading.

Midway has a non GI Throat Erosion Gage with swap-able center sections that allow you to interchange lengths for M1, M14 and 1903.



January 08, 2009, 19:59
I have a NOS Garand barrel from Jim Leatherwood. Someone stole my throat gauge some years ago, so I do not have one.

Anyone in the area with a throat gauge is welcome to come and measure it.