Taping a Go-Guage to get a no go gauge.

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D51208

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RCMODEL posted on one of my other threads about applying tape to a go gauge to get a no go gauge.

RC or anyone else who knows how, where do you apply the tape on the go gauge? How thick should the total tape be? Also how thick should the head space gauge now be when it has the tape on it?

could you post a picture please?

Thanks for the help!
 
If it is possible to tape a go-gage it is possible to tape a case, if you were able to measure the length of the case from the head of the case to it's shoulder you would not need the head space gage.

If I was going to add to the length of the gage I would add the tape to the part of the gage that goes against bolt face, adding to the shoulder of the gage gets very complicated when working with the cone and apex.

F. Guffey
 
forgive, as to the last part, the difference between go-gage and no go-gage length is different for different chambers, I make gages in different length, some times in thousands.

There is .004 thousands difference in length between the 30/06 go-gage and the no go-gage.

It would help if you listed the chamber.

F. Guffey

this early? I do not use spell check.
 
I'm not to worried about spelling haha. The chamber is for an ar-15 chambered in 5.56.
 
Like fguffey said, "There is .004 thousands difference in length between the 30/06 go-gage and the no go-gage."

Thin beer can metal will be close to .004in . Find the thinnest (cheapest) can you can. Check with a Mic.
Put the shim between the boltface and the go gauge. It looks like the difference in a 223 go / no-go is 0.003in.
 
As I posted before, Scotch "Magic" tape is .0015" thick, or close enough.

Two layers on the rim of the GO gage, and trimmed around the "case gage rim" edge with an xacto knife so it doesn't hang over the edge, is .003".

Three layers is .0045" and should be NO GO in a .223.

But tape is tape.
You can't muscle it trying to close the bolt on it or it will squish it.

As rooster59 said, measure some beer or pop can aluminum, or you can get brass or steel shim stock in about any thickness at any good auto repair store.


rc
 
Chamber guages

Buy yourself a field guage for the AR the standard go-nogo guages are not for AR type rifles. Al
 
Or learn to determine the length of the chamber without a head space gage, I do not shoot gages, and I do not fire form, I form first, then fire.


F. Guffey
 
Fguffey, I looked at my Forster .30-06 headspace gages and the difference between go and no go is .006"
 
I assume the barrel came w/ the extension installed, correct? If so, I would shoot it and check the fired brass with a case guage. You're not setting headspace; you're checking it, correct?

Edit: I will add, this is not the proper way to do it, it's just the way most folks do it.

Edit, Edit: We are talking about a AR rifle?
 
Yep, it comes with the extension and yep we are talking about an ar-15.

Yep just checking it to make sure there is no catastrophic malfunctions and that there wont be any.
 
A smith can check it for less cost than buying gauges and assuming you have a good smith, you'll know it's right.

I just shoot it and check the fired case in a case gauge (if you reload, you probably have one). I think most people just shoot it and stop at that. I can't tell you this is the correct way to go, so you'll have to make your own mind up on that. FWIW, my smith told me he has yet to run across a new Barrel/Extension/Bolt that didn't check. If you are re-barreling an old rifle, I would swap out the bolt for a new one.
 
Apply the tape to the back of the go gage. One layer of taper will get you to 1/2 the distance to the no go gage....so still acceptable for headspace (for me this is more accurate anyway), and 2 layers of scotch tape will get you to where you need for a no go gage.
 
Taping headspace guages

DON'T DO IT PERIOD, if you have to do something like this use metal shims they come in different thicknesses and can be cut with sissors in round shape to fit in bolt face.You can get them at auto parts stores or places that sell bearings, they are easy to make and will not rool-up when bolt face is turning to lock-up, put a little oil on the bolt face to hold them in place, also remove the ejector plunger to get a better reading. Head space guage dimensions for .223 are as follows ( GO=1.4636" ) ( NO-GO=1.4666) (Field=1.4696) . The FIELD GUAGE is ( .003" LONGER THAN NO-GO ) and is recommended for AR's because they need the extra space to function. Buy yourself a field guage for your AR and go shoot. Al
 
For CHECKING a rifle what you really need is a field gauge, correct? As long os the bolt won't close on a field gauge then you don't have an unsafe headspace condition.

A go gauge is most useful when setting headspace, especially on a Savage-type rifle where you can just screw the barrel down against the gauge and that sets it for minimum headspace. For fitting prefit barrels on a Mauser where you need to use a reamer I would like to also have a no-go just to make sure I didn't go too far.
 
AR headspacing

What is recommended for AR's is to use a field guage. The bolt should close on the field guage, as shown in the DVD that is sold by Brownell's and that is what I've used and the AR's it worked fine. The bolt action guns work with go and no-go guages, however I final fit mine with loaded rounds to get a tighter headspace, about .0015" is what I like. Al
 
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