M14 Forum

art luppino

This gauge was designed to measure the distance erosion has advanced the rifling towards the muzzle from what the reading was when the barrel was unfired. This measurement equates to barrel wear. The gauge does not indicate the quality of the barrel. It offers an indication of wear.

One of the values of the gauge for competitive shooters is it tells them it is time for a barrel change, nobody should start a shooting season with a barrel that has a high reading. Although, there have been cases where high erosion barrels continued to shoot high scores, there are no cases where high muzzle reading produced quality scores.

Another value of the gauge is, it assists individuals in either buying or rejecting used barrels. Again, high muzzle wear is always an excellent reason for rejection. For the shooter that intends to use the gauge, it should be used to get a reading when the barrel is new, note that reading and measure as rifle is fired to keep record of advancement, this will give you time to start a search for a replacement barrel. If you do not know what the new reading was you have no starting place to measure from, only a guess.

Different chamber reamers cut different leads and will give reading when new that otherwise may be a reason for rejection.

You are probably asking, if all this true, why have a guage? They do serve as an indicator, they confirm expectations. If you expect it may be shot out, it probably is. Most of all, they can prevent you from wasting your money.Art

GARRARD

How much does the gauge cost?

WrenchDevil6

Try here.

Visigoth9

Hey Art

I get that the throat on any given barrel when new may be anywhere from "zero" to something above that. As such the TE gauge is a good wear indicator if one has the original baseline.

Now my question is about chrome-lined barrels. If I am showing erosion readings based on an original "zero-point reading" I can assume the first thing to go to hell is the chromium plating.

Aside from eye-balling the start of the lands and grooves from the chamber end...if I have a "as-new" TE reading,,,,is there a "wear value" that can be determined on a standard TE gauge with a GI barrel that tells me when the chrome is shot out/or off the chamber end of the bore?

I am guessing that the chrome lining is GI spec'd to a certain thickness and if there is a way to translate that thickness (or loss thereof) into a TE gauge "increment reading"

just pondering here

dprice3844444

https://www.standardpartsllc.com/pro...?idCategory=14


gauges for 3006 and 308

Major Stuph

Of my years building M14s & M1As the Milt. gauges are good for military throats as Art stated. A commercial barrel (CB) will read different due to a different throat cut. Some CBs will measure 2.5 to 3 new. That only means that's a start for your data book just watch the numbers from that point. Add 4 or 5 to your start number and it's time for a new barrel. Another trick is to take a 308 shell and split the neck down to the shoulder (one cut with a dremel cutting wheel) and drill a round hole at the end of the split. Now pinch the neck so it will hold a bullet (seated long) and push the assembly into the chamber. Pull same out (a screw driver under the extractor groove works) and measure over all length (OAL). Do this a minumum of three times. Once you have the same measurement log that into your data book. Use that as your reference point for that particular bullet. The ojives of most bullets are all different so will have a different OAL. I believe my Noslers 168 and 175s are about the same measurement! This is very accurate. A new, new barrel will give problems due to the sharp edges of the throat and will grab the bullet and leave it in the chamber. You should shoot about 100 rds before taking a measurement.

losok

Major Stuph, good point I was about to make on the measuring of new barrels. I dont want guys to panic if they measure a new barrel, unfired and then measure after 1000 rounds. Most folks dont understand that if you measure new, they are catching a false reading from the roughness of the initial chamber cut, this will give a false low reading.

Most barrels will loosen up around .01 to .015 in the first thousand round, and then slow down considerably in the rate of erosion. For instance I have a customer who checks his religiously, he jumped from where I shipped it to him out to .012 in 1k rounds, then then to .015 in the next thousand. This is a guy who shoots hot 30-06 loads. He shoots the 208AMAX and 210 Bergers at 2700 to 2800 out of a 22 inch tube on his custom bolt rifle.

Major Stuph

A real EYE OPENER is to take a 6 or 8" .30 cal. barrel stub and then chuck into the 3 jaw and just run a finish reamer until the shoulder is about .300 or so deep. Only that deep so you can get a good look at the throat. Now take that stub into the bright sunlight with a 10X loupe and look, at an angle, at the ream marks on the leade/throat - scary!! Also the ream marks elsewhere. The elsewere are usually polished out to some degree. I guess the throat polishing kits with the treated bullets do have some merit. Interestingly enough, I have had some barrels (M14/M1A) from the same maker (no longer available from the NW) that the rifling look as if it was put into the barrel with a corn cob button/reamer. But did those barrels ever shoot!!! So go figure.